New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'ankor@dixie-net.com'
ankor@dixie-net.com answered: 15637 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149 , 9150..9179 , 9180..9209 , 9210..9239 , 9240..9269 , 9270..9299 , 9300..9329 , 9330..9359 , 9360..9389 , 9390..9419 , 9420..9449 , 9450..9479 , 9480..9509 , 9510..9539 , 9540..9569 , 9570..9599 , 9600..9629 , 9630..9659 , 9660..9689 , 9690..9719 , 9720..9749 , 9750..9779 , 9780..9809 , 9810..9839 , 9840..9869 , 9870..9899 , 9900..9929 , 9930..9959 , 9960..9989 , 9990..10019 , 10020..10049 , 10050..10079 , 10080..10109 , 10110..10139 , 10140..10169 , 10170..10199 , 10200..10229 , 10230..10259 , 10260..10289 , 10290..10319 , 10320..10349 , 10350..10379 , 10380..10409 , 10410..10439 , 10440..10469 , 10470..10499 , 10500..10529 , 10530..10559 , 10560..10589 , 10590..10619 , 10620..10649 , 10650..10679 , 10680..10709 , 10710..10739 , 10740..10769 , 10770..10799 , 10800..10829 , 10830..10859 , 10860..10889 , 10890..10919 , 10920..10949 , 10950..10979 , 10980..11009 , 11010..11039 , 11040..11069 , 11070..11099 , 11100..11129 , 11130..11159 , 11160..11189 , 11190..11219 , 11220..11249 , 11250..11279 , 11280..11309 , 11310..11339 , 11340..11369 , 11370..11399 , 11400..11429 , 11430..11459 , 11460..11489 , 11490..11519 , 11520..11549 , 11550..11579 , 11580..11609 , 11610..11639 , 11640..11669 , 11670..11699 , 11700..11729 , 11730..11759 , 11760..11789 , 11790..11819 , 11820..11849 , 11850..11879 , 11880..11909 , 11910..11939 , 11940..11969 , 11970..11999 , 12000..12029 , 12030..12059 , 12060..12089 , 12090..12119 , 12120..12149 , 12150..12179 , 12180..12209 , 12210..12239 , 12240..12269 , 12270..12299 , 12300..12329 , 12330..12359 , 12360..12389 , 12390..12419 , 12420..12449 , 12450..12479 , 12480..12509 , 12510..12539 , 12540..12569 , 12570..12599 , 12600..12629 , 12630..12659 , 12660..12689 , 12690..12719 , 12720..12749 , 12750..12779 , 12780..12809 , 12810..12839 , 12840..12869 , 12870..12899 , 12900..12929 , 12930..12959 , 12960..12989 , 12990..13019 , 13020..13049 , 13050..13079 , 13080..13109 , 13110..13139 , 13140..13169 , 13170..13199 , 13200..13229 , 13230..13259 , 13260..13289 , 13290..13319 , 13320..13349 , 13350..13379 , 13380..13409 , 13410..13439 , 13440..13469 , 13470..13499 , 13500..13529 , 13530..13559 , 13560..13589 , 13590..13619 , 13620..13649 , 13650..13679 , 13680..13709 , 13710..13739 , 13740..13769 , 13770..13799 , 13800..13829 , 13830..13859 , 13860..13889 , 13890..13919 , 13920..13949 , 13950..13979 , 13980..14009 , 14010..14039 , 14040..14069 , 14070..14099 , 14100..14129 , 14130..14159 , 14160..14189 , 14190..14219 , 14220..14249 , 14250..14279 , 14280..14309 , 14310..14339 , 14340..14369 , 14370..14399 , 14400..14429 , 14430..14459 , 14460..14489 , 14490..14519 , 14520..14549 , 14550..14579 , 14580..14609 , 14610..14639 , 14640..14669 , 14670..14699 , 14700..14729 , 14730..14759 , 14760..14789 , 14790..14819 , 14820..14849 , 14850..14879 , 14880..14909 , 14910..14939 , 14940..14969 , 14970..14999 , 15000..15029 , 15030..15059 , 15060..15089 , 15090..15119 , 15120..15149 , 15150..15179 , 15180..15209 , 15210..15239 , 15240..15269 , 15270..15299 , 15300..15329 , 15330..15359 , 15360..15389 , 15390..15419 , 15420..15449 , 15450..15479 , 15480..15509 , 15510..15539 , 15540..15569 , 15570..15599 , 15600..15629 , 15630..15659, >>NextLinear_Equations_And_Systems_Word_Problems/470421: The Acme Class Ring Company designs and sells two types of rings: the VIP and the SST. The company can produce up to 56 rings each day, using up to 140 total man-hours of labor. It takes 7 man-hours to make one VIP ring and 2 man-hours to make one SST ring. Let x represent the number of VIP rings, and let y represent the number of SST rings. Including the system inequalities and , find the remaining inequalities that best describe this company's ring production. 1 solutions
Answer 322893 by ankor@dixie-net.com(15652) on 2011-07-15 16:49:44 (Show Source):
You can put this solution on YOUR website!The Acme Class Ring Company designs and sells two types of rings:
the VIP and the SST.
The company can produce up to 56 rings each day, using up to 140 total man-hours of labor.
It takes 7 man-hours to make one VIP ring and 2 man-hours to make one SST ring.
Let x represent the number of VIP rings, and let y represent the number of SST rings.
Including the system inequalities and, find the remaining inequalities that best describe this company's ring production.
:
No. of rings
x + y =< 56
:
Labor:
7x + 2y =< 140
:
x=>0
y=>0
|
Pythagorean-theorem/470710: A window washer leans a ladder up against a wall so that the top of the ladder touches the base of the window ,as shown below .The bottom of the ladder is 15 feet from the wall ,and the base of the window is 26 feet from the ground .what is the length of the ladder to the nearest foot? 1 solutions
Answer 322892 by ankor@dixie-net.com(15652) on 2011-07-15 16:44:33 (Show Source):
You can put this solution on YOUR website!A window washer leans a ladder up against a wall so that the top of the ladder
touches the base of the window ,as shown below .
The bottom of the ladder is 15 feet from the wall ,and the base of the window is 26 feet from the ground .
what is the length of the ladder to the nearest foot?
:
This is a right angle triangle problem, c^2 = a^2 + b^2
Where
a = 15
b = 26
c = length of ladder
:
c^2 = 15^2 + 26^2
c^2 = 225 + 676
c = 
c ~ 30 ft ladder
|
Trigonometry-basics/470426: f the radius of a circle is 11 cm, the degree measure of an angle subtended by an arc of length 13 cm is _____o. Round to one decimal place.
Answer 1 solutions
Answer 322890 by ankor@dixie-net.com(15652) on 2011-07-15 16:37:28 (Show Source):
You can put this solution on YOUR website!If the radius of a circle is 11 cm, the degree measure of an angle subtended by an
arc of length 13 cm is _____o. Round to one decimal place.
:
Find the circumference of the circle

C = 69.115 cm
:
Find the degrees of a 13 cm arc
 * 360 = 67.7 degrees
|
Age_Word_Problems/470424: In 2011, a man was 40 and his daughter was 12. In what year was the man just twice his daughter's age? 1 solutions
Answer 322721 by ankor@dixie-net.com(15652) on 2011-07-14 21:32:01 (Show Source):
You can put this solution on YOUR website!n 2011, a man was 40 and his daughter was 12.
In what year was the man just twice his daughter's age?
:
t = no. of years for this to be true
:
40 + t = 2(12+t)
40 + t = 24 + 2t
40 - 24 = 2t - t
16 = t
:
2011 + 16 = 2027, this will be true
:
:
See if this is true
40+16 = 2(12+16)
56 = 2(28)
|
Numbers_Word_Problems/470403: A shade of green paint is made by mixing 3 parts of blue paint with 7 parts of yellow paint. How much yellow paint is needed to make 70 quarts of green paint?
Thank you much appreciated 1 solutions
Answer 322718 by ankor@dixie-net.com(15652) on 2011-07-14 21:24:39 (Show Source):
You can put this solution on YOUR website!A shade of green paint is made by mixing 3 parts of blue paint with 7 parts of yellow paint.
How much yellow paint is needed to make 70 quarts of green paint?
:
Let x = the multiplier
3x + 7x = 70
10x = 70
x = 7 is the multiplier
therefore
7*7 = 49 qts of yellow paint
and
7*3 - 21 qts of blue paint
|
Volume/470497: Hello I would like someone to help me understand how to do this queston thank you very much. What is the cost of concrete for a walkway that is 15 feet long, 8 feet wide, and 9 inches deep if the concrete costs $30. per cubic yard? 1 solutions
Answer 322715 by ankor@dixie-net.com(15652) on 2011-07-14 21:16:30 (Show Source):
You can put this solution on YOUR website!What is the cost of concrete for a walkway that is 15 feet long, 8 feet wide,
and 9 inches deep if the concrete costs $30. per cubic yard?
:
Change 9 inches to .75 ft
:
Find the vol in cu/ft, change to cubic yards, multiply by $30
 * 30 = $100
|
Linear-equations/469698: The question is: Solve each system by elimination.
x-y=11
2x+y=19
How do I do this? In dummy language please. I want to actually understand what it is I'm suppose to be doing. Thanks much! 1 solutions
Answer 322345 by ankor@dixie-net.com(15652) on 2011-07-13 10:44:50 (Show Source):
You can put this solution on YOUR website!Solve each system by elimination.
Just add the two equations, this will eliminate y, leaving x
x - y = 11
2x+ y = 19
-------------
3x + 0 = 30
3x = 30
divide both sides by 3
1x =
x = 10
:
Use the 2nd equation to find y
2x + y = 19
Replace x with 10
2(10) + y = 19
20 + y = 19
subtract 20 from each side
y = 19 - 20
y = -1
:
The solutions: x = 10, y = -1
:
:
Check this using the 1st equation
x - y = 11
Replace x with 10 and y with -1, see if it is true
10 - (-1) = 11
minus a minus is a plus, therefore
10 + 1 = 11; confirms our solution
|
Expressions-with-variables/469705: Fred can paint a house in 10 hours. Together, Pat and Fred can paint the house in 8 hours. Which equation, when solved, will produce the number of hours needed for Pat to paint the house alone? 1 solutions
Answer 322228 by ankor@dixie-net.com(15652) on 2011-07-12 19:33:25 (Show Source):
You can put this solution on YOUR website!Fred can paint a house in 10 hours.
Together, Pat and Fred can paint the house in 8 hours.
Which equation, when solved, will produce the number of hours needed for Pat to paint the house alone?
;
Let t = time required by Pat to do the job alone
Let the completed job = 1 (a painted house)
:
Each man will do a fraction of the job, the sum of the two fractions = 1
;
 +  = 1
multiply by 10t, results:
8t + 8(10) = 10t
80 = 10 - 8t
80 = 2t
t = 
t = 40 hrs, for Pat to do it alone, (fire this guy)
:
Check this
8/10 + 8/40 =
.8 + .2 = 1
|
Travel_Word_Problems/469663: A train starts its 221 mile trip at 7:30 A.M. If the train travels at an average speed of 34 miles per hour and stops exactly four minutes at each of ten stations, at what time in the afternoon will it arrive at its final destination? 1 solutions
Answer 322216 by ankor@dixie-net.com(15652) on 2011-07-12 16:55:25 (Show Source):
You can put this solution on YOUR website!A train starts its 221 mile trip at 7:30 A.M. If the train travels at an average
speed of 34 miles per hour and stops exactly four minutes at each of ten
stations, at what time in the afternoon will it arrive at its final destination?
:
total time (t) = travel time (hrs) + stop time (min)
t =  + 10(4)
t = 6.5 hrs + 40 min: converts to 7 hrs 10 min
7:30 AM + 7:10 = 2:40 PM
|
Travel_Word_Problems/469609: Kam traveled 240 miles east of St. Louis. For most of the trip he averaged 70mph, but for one period of time he slowed to 20 mph due to heavy traffic. If the total time of travel was 7 hours, how many miles did he travel at the reduced speed? 1 solutions
Answer 322215 by ankor@dixie-net.com(15652) on 2011-07-12 16:45:59 (Show Source):
You can put this solution on YOUR website!Kam traveled 240 miles east of St. Louis. For most of the trip he averaged 70mph,
but for one period of time he slowed to 20 mph due to heavy traffic.
If the total time of travel was 7 hours, how many miles did he travel at the reduced speed?
:
Let r = total miles at reduced speed
then
(240-r) = total miles at 70 mph
:
Write a time equation, time = dist/speed
:
Fast time + slow time = 7 hrs
 +  = 7
Multiply by 140 to clear the denominators, results:
2(240-r) + 7r = 140(7)
480 - 2r + 7r = 980
-2r + 7r = 980 - 480
5r = 500
r = 
r = 100 mi at 20 mph
:
:
See if that adds up, find the times:
(240-100)/70 = 2 hrs
100/20 = 5 hrs
------------------
total time = 7 hrs
|
Miscellaneous_Word_Problems/469453: Can someone Please help me?
Solved by the substitution method
6x+2y=-46
-7x+y=57 1 solutions
Answer 322210 by ankor@dixie-net.com(15652) on 2011-07-12 16:26:11 (Show Source):
You can put this solution on YOUR website!Solve by the substitution method
6x + 2y =-46
-7x+ y = 57
:
Use the 2nd equation for substitution in the 1st equation
-7x + y = 57
y = 7x + 57
:
Replace y with (7x+57) in the 1st equation
6x + 2(7x+57) = -46
6x + 14x + 114 = -46
6x + 14x = -46 - 114
20x = -160
x = 
x = -8
:
Find y, substitute -8 for x in: y = 7x + 57
y = 7(-8) + 57
y = -56 + 57
y = 1
:
Check solutions in the 1st equation: 6x + 2y =-46
6(-8) + 2(1) =
-48 + 2 = -46, confirms our solutions of x=-8, y=1
|
logarithm/469490: The Greek God Zeus ordered his blacksmith Hephaestus to create a perpetual water-making machine to fill Zeus' mighty chalice. The volume of Zeus' chalice was reported to hold about one hundred and fifty sextillion gallons (that is a fifteen followed by twenty-two zeros). If Hephaetus' machine pours out 2 gallon in the first minute and then doubles its output each minute, find in which minute would this hypothetical machine pour out a single quantity of water that would be enough to fill Zeus' chalice with water?
hr. min.
This one is very hard to do. I would like to know how this one is supposed to be solved.Thanks and have a great day! 1 solutions
Answer 322110 by ankor@dixie-net.com(15652) on 2011-07-12 09:18:29 (Show Source):
|
Age_Word_Problems/469397: The sum of the ages of a gold coin and a silver coin is 65 years. The age of the gold coin 10 years from now will be 10 years less than the age of the silver coin 5 years ago. Find the present ages of the two coins. Gold coin --- yr. Silver coin--- yr. I got 1996 for the gold coin and 1971 for the silver coin. 1 solutions
Answer 322106 by ankor@dixie-net.com(15652) on 2011-07-12 08:57:59 (Show Source):
You can put this solution on YOUR website!The sum of the ages of a gold coin and a silver coin is 65 years.
The age of the gold coin 10 years from now will be 10 years less than the age of the silver coin 5 years ago.
Find the present ages of the two coins. Gold coin --- yr. Silver coin--- yr.
:
Let g = age of the gold coin
Let s = age of the silver
:
Write an equation for each statement:
:
"The sum of the ages of a gold coin and a silver coin is 65 years."
g + s = 65
:
"The age of the gold coin 10 years from now will be 10 years less than the age of the silver coin 5 years ago."
g + 10 = (s-5) - 10
g + 10 = s - 15
g = s - 15 - 10
g = s - 25
Put equation into the standard form, add to the 1st equation
g - s = -25
g + s = 65
---------------addition eliminates s, find g
2g = 40
g = 20 yrs, age of the gold
then
20 + s = 65
s = 65 - 20
s = 45 yrs age of the silver
;
:
See if that works in the statement
" The age of the gold coin 10 years from now will be 10 years less than the age of the silver coin 5 years ago. "
20 + 10 = (45 - 5) - 10
30 = 40 - 10
:
|
Quadratic_Equations/469064: Help! I asked earlier and I have tried but I do not even understand the question. Can someone please help me understand these two?
Determine the nature of the solutions of the equations.
y^2=1/5y+2/3
x^2-4=0
Is there one real solution, two real solutions, or two non real solutions?
I believe that the first one has 2 real solutions and that the second one has two non real solutions. Did I even come close? 1 solutions
Answer 321943 by ankor@dixie-net.com(15652) on 2011-07-11 17:12:08 (Show Source):
You can put this solution on YOUR website!Determine the nature of the solutions of the equations.
y^2=1/5y+2/3
x^2-4=0
:
You do this by using the rules of the discriminant
:
The equation should be in the form ax^2 + bx + c
:
The discriminant: d = b^2 - 4*a*c
The rules,
If d > 0 there are two distinct real roots (solutions)
If d = 0 there is one real solution(a double root)
If d < 0 there is two imaginary roots, one the conjugate of the other
:
Put the 1st equation in ax^2 + bx + c form
y^2 -  y - 
then
a=1
b= 
c= 
d =  - 4 * 1 * 
d =  - 
which is
d =  + 
d > 0, therefore there are two distinct real roots, (the exact value is not needed) so you are right.
:
the 2nd equation is in ax^2 + bx + c form
x^2 - 4 = 0
a=1
b=0
c=-4
d = -4*1*-4
d = +16 > 0, also two distinct real roots
:
You can see that if you solve it
x^2 -4 = 0
x^2 = 4
x = +/- 
x = +2
and
x = -2
|
Travel_Word_Problems/469146: Jenny went on a road trip to Chicago. On her trip she averaged 68 miles per hour. What was her average speed in feet per minute? 1 solutions
Answer 321939 by ankor@dixie-net.com(15652) on 2011-07-11 16:21:03 (Show Source):
You can put this solution on YOUR website!Jenny went on a road trip to Chicago.
On her trip she averaged 68 miles per hour.
What was her average speed in feet per minute?
"
Convert to feet per hr, divide by 60 to convert ft/min
 = 5,984 ft per min (a little over a mile per minute)
|
Age_Word_Problems/469231: what is Diaphanous's age?
Diaphanous was a famous Greek mathematician who lived and worked in Alexandria, Egypt, probably in the third century C.E. When he died, someone described his life in this puzzle. He was a boy for 1/6 of his life. after 1/12 more, he acquired a beard. After another 1/7, he married. in the fifth year of marriage, his son was born. The son lived half as many years as his father. Diaphanous died 4 years after his son. How old was Diaphanous when he died 1 solutions
Answer 321917 by ankor@dixie-net.com(15652) on 2011-07-11 14:34:20 (Show Source):
You can put this solution on YOUR website! He was a boy for 1/6 of his life. after 1/12 more, he acquired a beard. After another 1/7, he married. in the fifth year of marriage, his son was born. The son lived half as many years as his father. Diaphanous died 4 years after his son. How old was Diaphanous when he died
Let x = his final age
:
a lengthy but simple equation
Final age = child + youth + bach + marriage + son's age + 4
x =  x +  x +  x + 5 +  x + 4
:
Common denominator of 12*7 = 84
x =  x +  x +  x + 5 +  x + 4
:
x =  x + 9
:
 x -  x = 9
:
 x = 9
:
x = 84 is his final age
:
Check:
14 + 7 + 12 + 5 + 42 + 4 = 84
|
Linear_Equations_And_Systems_Word_Problems/468781: One hour after a truck has left on an overnight haul, a messenger on a motorcycle leaves from the same starting point to overtake the truck. If the messenger travels at an average rate of 65 mi/h and overtakes the truck in 4 hours, what is the average rate of the truck? 1 solutions
Answer 321787 by ankor@dixie-net.com(15652) on 2011-07-10 20:20:46 (Show Source):
You can put this solution on YOUR website!One hour after a truck has left on an overnight haul, a messenger on a motorcycle
leaves from the same starting point to overtake the truck.
If the messenger travels at an average rate of 65 mi/h and overtakes the truck
in 4 hours, what is the average rate of the truck?
:
Let s = the speed of the truck
:
We are given the travel time of the Motorcycle as 4 hrs
then
the travel time of the truck is one hr longer: 5 hrs
:
When motorcycle overtakes the truck, they will have traveled the same distance
:
Write a distance equation, dist = speed * time
:
truck dist = motorcycle dist
5s = 65(4)
5s = 260
s = 
s = 52 mph is the speed of the truck
:
:
:
see if this is true find the distance of each
4*65 = 260 mi
5*52 = 260 mi
|
Miscellaneous_Word_Problems/468796: During the first part of a trip a canoeist travels 45 miles at a certain speed. The canoeist travels 12 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 4 hrs. What was the total time on each trip? 1 solutions
Answer 321693 by ankor@dixie-net.com(15652) on 2011-07-10 12:23:17 (Show Source):
You can put this solution on YOUR website!During the first part of a trip a canoeist travels 45 miles at a certain speed.
The canoeist travels 12 miles on the second part of the trip at a speed 5 mph slower.
The total time for the trip is 4 hrs.
What was the total time on each trip?
:
Let s = speed for the 1st 45 mi
then
(s-5) = speed for the last 12 mi
:
Write a time equation, time = dist/speed
:
1st part time + 2nd part time = 4 hr
 +  = 4
multiply by s(s-5), results:
45(s-5) + 12s = 4s(s-5)
:
45s - 225 + 12s = 4s^2 - 20s
57s - 225 = 4s^2 - 20s
Arrange as a quadratic on the right
0 = 4s^2 - 20s - 57s + 225
:
4s^2 - 77s + 225 = 0
Solve this with the quadratic formula,

In this problem we have:

Do the math, only one solution will make sense
|
Equations/468858: Write an equation wher 6 must be added to each side to solve the equation and the solution is a negative number
1 solutions
Answer 321676 by ankor@dixie-net.com(15652) on 2011-07-10 10:45:39 (Show Source):
You can put this solution on YOUR website!rite an equation where 6 must be added to each side to solve the equation and the solution is a negative number
:
3x - 6 = -15
Add 6 to both side
3x - 6 + 6 = -15 + 6
3x = -9
x = 
x = -3
|
logarithm/468741: The population P of a city is given by
P = 10000 e^kt
t represents the year, with t - 100 correspoding to 2000
In 1955, the population was 3350 Find the value of k and use this result to predict te population in the year 2007. 1 solutions
Answer 321619 by ankor@dixie-net.com(15652) on 2011-07-09 21:33:52 (Show Source):
You can put this solution on YOUR website!Please resubmit this,
"the statement "t represents the year, with t - 100 corresponding to 2000" has got me unable to sort this one out. Perhaps someone else can. Sorry. C
|
Linear-equations/468688: Please help me with this algebra problem. Thank you so much.
The salmon population in a particular stream in Alaska decreased from 148,000 in 1997 to 129,000 in 2002 predict the salmon population in 2015. Please show work. 1 solutions
Answer 321616 by ankor@dixie-net.com(15652) on 2011-07-09 21:16:24 (Show Source):
You can put this solution on YOUR website!The salmon population in a particular stream in Alaska decreased from 148,000 in 1997 to 129,000 in 2002
predict the salmon population in 2015.
:
Find the slope (m)
let x1 = 0, representing 1997
let x2 = 5, representing 2002
then
y1 = 148000; representing the salmon numbers
y2 = 129000
:
m = 
:
m =  =  = -3800 is the slope
:
Find the equation using the point/slope form: y - y1 = m(x - x1)
y - 148000 = -3800(x - 0)
y = -3800x + 148000; is the equation
:
"predict the salmon population in 2015"
x = 18
y = -3800(18) + 148000
y = -68400 + 148000
y = 79,600 Salmon in 2015
:
Hey, did this make sense to you now! Not that hard, right?
|
Polynomials-and-rational-expressions/468717: 8. Find all complex zeros for the following polynomial function. Please show all of your work.
f(x)=x³-5x²+49x-245
I need some help can you help please? thank you. 1 solutions
Answer 321598 by ankor@dixie-net.com(15652) on 2011-07-09 19:34:04 (Show Source):
You can put this solution on YOUR website!8. Find all complex zeros for the following polynomial function. Please show all of your work.
f(x)=x³-5x²+49x-245
Make it equal to zero and Group factor
x^3 - 5x^2 + 49x - 245 = 0
(x^3 + 49x) - (5x^2 + 245) = 0
x(x^2 + 49) - 5(x^2 + 49) = 0
Factor out (x^2+49) leaving
(x^2 + 49)(x - 5) = 0
x^2 = -49
x = 
x = +7i
x = -7i
and
x = 5 is the only real root
:
|
Radicals/468568: Solve the equation a²+b²=c² for b
suppose that an isosceles right triangle has a hypotenuese with length 30cm
I do not understand this equation or how to solve for b, when I have not been given a and c. I am confused on this.
Then next "What are the lengths of the triangle?" 1 solutions
Answer 321563 by ankor@dixie-net.com(15652) on 2011-07-09 15:03:27 (Show Source):
You can put this solution on YOUR website!Solve the equation a²+b²=c² for b
suppose that an isosceles right triangle has a hypotenuse with length 30cm.
:
Note that in an isosceles right triangle, a and b are equal, you are given the
hypotenuse as 30 cm, therefore:
:
a = b
c = 30
therefore
b^2 + b^2 = 30^2
2b^2 = 900
b^2 = 900/2
b^2 = 450
b =  or 
b ~ 21.2132
:
"What are the lengths of the triangle?"
b = 21.2132
a = 21.2132
c = 30
|
Word_Problems_With_Coins/468330: sarah has a collection of 80 coins made up of nickels, dimes. and quarters. she has 5 more dimes than one-third the number of nickels, and the number of quarters is one less than one-fourth the number of nickels. how many coins of each kind does she have? 1 solutions
Answer 321454 by ankor@dixie-net.com(15652) on 2011-07-08 21:45:53 (Show Source):
You can put this solution on YOUR website!sarah has a collection of 80 coins made up of nickels, dimes. and quarters.
she has 5 more dimes than one-third the number of nickels, and the number of
quarters is one less than one-fourth the number of nickels.
how many coins of each kind does she have?
:
Let n = no. of nickels
Let d = no. of dimes
Let q = no. of quarters
:
Write an equation for each statement:
"sarah has a collection of 80 coins made up of nickels, dimes. and quarters."
n + d + q = 80
:
"she has 5 more dimes than one-third the number of nickels,"
d =  n + 5
:
" the number of quarters is one less than one-fourth the number of nickels."
q =  n - 1
:
Replace d and q from the above equations:
n + (  n + 5) + (  n - 1) = 80
:
n +  n +  n - 1 + 5 = 80
:
n +  n +  n + 4 = 80
:
n +  n +  n = 80 - 4
:
n +  n +  n = 76
Get rid of those annoying fractions multiply by 12
12n + 4n + 3n = 12(76)
19n = 912
n = 
n = 48 nickels
then
d =  *48 + 5
d = 16 + 5
d = 21 dimes
and
q =  *48 - 1
q = 12 - 1
q = 11 quarters
:
:
Check this: 48 + 21 + 11 = 80
how many coins of each kind does she have?
|
Exponential-and-logarithmic-functions/468305: The half-life of a radioactive substance is the time it takes for half of the substance to decay. The half-life of carbon-14 is 5700 years.
a. Write an exponential function to model the decay of a 470-mg sample.
b. Explain what each value in the function model represents.
c. To the nearest hundredth, find the amount of carbon-14 remaining after 2619 years. Explain how you found this amount. 1 solutions
Answer 321431 by ankor@dixie-net.com(15652) on 2011-07-08 20:09:09 (Show Source):
You can put this solution on YOUR website!The half-life of a radioactive substance is the time it takes for half of the substance to decay.
The half-life of carbon-14 is 5700 years.
:
a. Write an exponential function to model the decay of a 470-mg sample.
A = 470*2^(-t/5700)
:
b. Explain what each value in the function model represents.
A = resulting amt after t yrs
470 = initial amt
5700 = half life of the substance
t = time of decay for the substance
:
c. To the nearest hundredth, find the amount of carbon-14 remaining after 2619 years.
Explain how you found this amount.
A = 470*2^(-2619/5700)
A = 470*2^-.45947
A = 470 * .727
A = 341.81 mg after 2619 yrs
:
You should be able to explain what we did here
|
Equations/468432: I need to use any method to solve:{x/2-y/4=-4
{X+y=-2 1 solutions
Answer 321430 by ankor@dixie-net.com(15652) on 2011-07-08 19:52:34 (Show Source):
You can put this solution on YOUR website!I need to use any method to solve:
 = -4
x + y = -2
:
Multiply the 1st equation by 4, resulting in
2x - y = -16
x + y = -2
----------------adding eliminates y, find x
3x = -18
x = 
x = -6
Find y
x + y = -2
-6 + y = -2
y = -2 + 6
y = 4
:
:
Check solutions, in the 1st original equation
 = -4
 = -4
 - 1 = -4
-3 - 1 = -4
|
Quadratic_Equations/468430: I have to complete the square to change the form of the function and grph the quadractic function????
f(x) = -2x^2 -5x +1 1 solutions
Answer 321428 by ankor@dixie-net.com(15652) on 2011-07-08 19:12:22 (Show Source):
You can put this solution on YOUR website!f(x) = -2x^2 - 5x + 1
:
-2x^2 - 5x + ___ = -1
divide by -2, change the signs
x^2 +  x + ___ = 
:
Find the term that will complete the square, add to both sides
Divide the coefficient of x by 2 and square it (5/4)^2 = 25/16
x^2 +  x +  =  + 
:
x^2 +  x +  =  + 
:
x^2 +  x +  = 
:
(x +  )^2 = 
:
x +  = +/- 
Two solutions
x =  +  
x = 
and
x =  -  
x = 
:
:
The graph
|
Miscellaneous_Word_Problems/468329: I have to find the area and perimeter of a rectangle. On the top of the rectangle is d+10 and on the right side of the rectangle just has a single d. How do I find these without having the length and width numbers? 1 solutions
Answer 321419 by ankor@dixie-net.com(15652) on 2011-07-08 18:47:00 (Show Source):
You can put this solution on YOUR website!I have to find the area and perimeter of a rectangle.
On the top of the rectangle is d+10 and on the right side of the rectangle just has a single d.
:
:
d has to be part of the answer
:
The perimeter:
p = 2(d+10) + 2d
p = 2d + 20 + 2d
p = 4d + 20
:
The area
A = d*(d+10)
A = d^2 + 10d
|
|