See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

Tutor:
New! Get regular updates about newly solved problems via algebra.com's RSS system.

Recent problems solved by 'josmiceli'

josmiceli answered: 9817 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, >>Next

Probability-and-statistics/720606: By using an appropriate average find out the average rate of motion in the case of a person who rides the first mile at the rate of 10 miles per hour, the next mile at the rate of 8 miles per hour and the third at the rate of 6 miles per hour.
1 solutions

Answer 441906 by josmiceli(9819) About Me  on 2013-03-01 05:00:01 (Show Source):
You can put this solution on YOUR website!
Average speed is always ( total distance / total time )
Total distance = +3+ mi
--------------
+t%5B1%5D+=+1%2F10+
+t%5B2%5D+=+1%2F8+
+t%5B3%5D+=+1%2F6+
--------------
Ave speed = +3+%2F+%28+1%2F10+%2B+1%2F8+%2B+1%2F6+%29+
Ave speed = +3+%2F++%28+24%2F240+%2B+30%2F240+%2B+40%2F240+%29+
Ave speed = +3+%2F+%28+94%2F240+%29+
Ave speed = +%28+3%2A240+%29+%2F+94+
Ave speed = +7.6596+ mi/hr
check:
+3+%2F+%28+.1+%2B+.125+%2B+.16667+%29+
+3+%2F+.39167++=+7.6595+
close enough


Linear-equations/720605: Kabir age is 20 years hence will be 3 time his age 12 years ago. Find Kabir present age.
1 solutions

Answer 441905 by josmiceli(9819) About Me  on 2013-03-01 04:45:37 (Show Source):
You can put this solution on YOUR website!
Let +x+ = his age now
+x+%2B+20+ = his age 20 years hence
+x+-+12+ = his age 12 years ago
given:
+x+%2B+20+=+3%2A%28+x+-+12+%29+
+x+%2B+20+=+3x+-+36+
+2x+=+56+
+x+=+28+
He is 28 now
-----------
check:
In 20 years he is 48
12 years ago he was 16
+48+=+3%2A16+
+48+=+48+
OK


Linear-equations/720611: write each equation in slope intercept form, and then find the slope and y intercept
2x-y=-15
1 solutions

Answer 441904 by josmiceli(9819) About Me  on 2013-03-01 04:40:03 (Show Source):
You can put this solution on YOUR website!
+2x+-+y+=+-15+
Subtract +2x+ from both sides
+-y+=+-2x+-+15+
Multiply both sides by +-1+
+y+=+2x+%2B+15+


Numeric_Fractions/720630: cows+hens=48 there less are 146 how many hens.
1 solutions

Answer 441903 by josmiceli(9819) About Me  on 2013-03-01 04:37:24 (Show Source):
You can put this solution on YOUR website!
They have 146 legs?
Let +c+ = number of cows
Let +h+ = number of hens
given:
(1) +c+%2B+h+=+48+
(2) +4c+%2B+2h+=+146+%7D%7D%0D%0A-------------------%0D%0A%282%29+%7B%7B%7B+2c+%2B+h+=+73+
Subtract (1) from (2)
(2) +2c+%2B+h+=+73+
(1) +-c+-+h+=+-48+
+c+=+25+
and, since
(1) +c+%2B+h+=+48+
(1) +25+%2B+h+=+48+
(1) +h+=+23+
There are 25 cows and 23 hens
check:
(2)
(2) +146+=+146+
OK


Angles/720629: How can I know what the value of x is in this question: Find the value of x in one angle, and the value of x + 20 in the other. But these two are complementary angles, how can I know so that the sum of x+x+20 totals to 90 degrees? And the 2 x's must be the same number? Please answer my question and put a solution and explanation.
1 solutions

Answer 441902 by josmiceli(9819) About Me  on 2013-03-01 04:28:37 (Show Source):
You can put this solution on YOUR website!
You have 2 angles that add up to 90 degrees
The angles are
+x+ and
+x+%2B+20+
Add the angles
+x+%2B+x+%2B+20+=+90+
+2x+%2B+20+=+90+
+2x+=+70+
+x+=+35+
+x+%2B+20+=+55+
So, the angles are 35 degrees and 55 degrees


Linear-equations/720609: 1. write each equation in slope-interceprt form, and them find the slope and y-intercept
3x+y=0


1 solutions

Answer 441901 by josmiceli(9819) About Me  on 2013-03-01 04:23:52 (Show Source):
You can put this solution on YOUR website!
+3x+%2B+y+=+0+
The slope intercept form looks like:
+y+=+m%2Ax+%2B+b+ where +m+ is the slope
+3x+%2B+y+=+0+
Subtract +3x+ from both sides
+y+=+-3x+
This is in the slope-intercept form
Note that +b+=+0+ and +m+=+-3+
Here's a plot of the equation:
+graph%28+400%2C+400%2C+-5%2C+5%2C+-5%2C+5%2C+-3x+%29+



Linear-equations/720612: write the equation of the line that passes through each pair of points in slope intercept form
(3,4),(4,6)
1 solutions

Answer 441900 by josmiceli(9819) About Me  on 2013-03-01 04:18:08 (Show Source):
You can put this solution on YOUR website!
Use the point-slope formula
+%28+y+-+4+%29+%2F+%28+x+-+3+%29+=+%28+6+-+4+%29+%2F+%28+4+-+3+%29+
+%28+y+-+4+%29+%2F+%28+x+-+3+%29+=+2+%2F+1+
+y+-+4+=+2%2A%28+x+-+3+%29+
+y+-+4+=+2x+-+6+
+y+=+2x+-2+
-------------
check:
(3,4)
+y+=+2x+-2+
+4+=+2%2A3+-2+
+4+=+6+-+2+
+4+=+4+
OK
(4,6)
+6+=+2%2A4+-+2+
+6+=+8+-+2+
+6+=+6+
OK


Age_Word_Problems/720620: if today a father is four times as old as his son and five years ago he was five times as old as his son, find their present age
1 solutions

Answer 441899 by josmiceli(9819) About Me  on 2013-03-01 04:12:56 (Show Source):
You can put this solution on YOUR website!
Let +f+ = Father's age now
Let +s+ = Son's age now
given:
(1) +f+=+4s+
(2) +f+-+5+=+5%2A%28+s+-+5+%29+
----------------------
(2) +f+-+5+=+5s+-+25+
(2) +5s+-+f+=+20+
By substitution:
(2) +5s+-+4s+=+20+
+s+=+20+
and
(1) +f+=+4s+
(1) +f+=+4%2A20+
(1) +f+=+80+
The Father is 80
The Son is 20
--------------
check:
5 years ago, the Father was +75+
5 years ago, the Son was +15+
+75+=+5%2A15+
+75+=+75+
OK


Travel_Word_Problems/720607: A JOGGER STARTS FROM ONE END OF A 15 MILE NATURE TRAIL AT 8:00 AM ONE HOUR LATER A CYCLIST STARTS FROM THE OTHER END OF THE TRAIL AND RIDES TOWARD THE JOGGER IF THE RATE OF THE JOGGER IS 6MPH AND THE RATE OF THE CYCLIST IS 9MPH AT WHAT TIME WILL THE TWO MEET?
THANK YOU
1 solutions

Answer 441898 by josmiceli(9819) About Me  on 2013-03-01 04:04:18 (Show Source):
You can put this solution on YOUR website!
You can think of the jogger as standing still and
the cyclist approaching at the sum of their speeds
-----------
The jogger cuts down the distance between them by
+d%5B1%5D+=+6%2A1+
+d%5B1%5D+=+6+ mi
So now the cyclist only has to travel +15+-+6+=+9+ mi
-----------
Let +t+ = the time in hrs it takes the cyclist to meet the jogger
+9+=+%28+6+%2B+9+%29%2At+
+9+=+15t+
+3+=+5t+
+t+=+3%2F5+ hrs
+%283%2F5%29%2A60+=+36+ min
The two will meet at 8:36 AM
-----------
check:
jogger's equation:
+d%5B2%5D+=+6%2A%283%2F5%29+
+d%5B2%5D+=+18%2F5+ mi
Cyclist's equation:
+d%5B3%5D+=+9%2A%283%2F5%29+
+d%5B3%5D+=+27%2F5+
+d%5B2%5D+%2B+d%5B3%5D+ must = 9 mi
+18%2F5+%2B+27%2F5+=+45%2F5+
+45%2F5+=+9+
OK


Mixture_Word_Problems/720623: Gus has on hand 5% alcohol solution and a 20% alcohol solution. He needs 30 liters of 10% alcohol solution. How many liters of each solution should he mix together to obtain the mixture he needs?
1 solutions

Answer 441897 by josmiceli(9819) About Me  on 2013-03-01 03:50:39 (Show Source):
You can put this solution on YOUR website!
Let +a+ = liters of 5% solution needed
Let +b+ = liters of 20% solution needed
-----------
(1) +a+%2B+b+=+30+
(2) +%28+.05a+%2B+.2b+%29+%2F+30+=+.1+
---------------------------
(2) +.05a+%2B+.2b+=+3+
(2) +5a+%2B+20b+=+300+
Multiply both sides of (1) by +5+ and
subtract (1) from (2)
(2) +5a+%2B+20b+=+300+
(1) +-5a+-+5b+=+-150+
+15b+=+150+
+b+=+10+
and, since
(1) +a+%2B+b+=+30+
(1) +a+=+20+
20 liters of 5% solution are needed
10 liters of 20% solution are needed
check answer:
(2) +%28+.05%2A20+%2B+.2%2A10+%29+%2F+30+=+.1+
(2) +%28+1%2B+2+%29+%2F+30+=+.1+
(2) +3%2F30+=+.1+
(2) +3+=+3+
OK


Mixture_Word_Problems/720619: How many liters of water must be added to 8 liters of a 40% salt solution to obtain a 10% salt solution?
1 solutions

Answer 441896 by josmiceli(9819) About Me  on 2013-03-01 03:41:53 (Show Source):
You can put this solution on YOUR website!
Let +w+ = liters of water to be added
+.4%2A8+=+3.2+ liters of salt in 40% solution
-----------
+3.2+%2F+%28+8+%2B+w+%29+=+.1+
+3.2+=+.1%2A%28+8+%2B+w+%29+
+3.2+=+.8+%2B+.1w+
+.1w+=+2.4+
+w+=+24+
24 liters of water must be added
check:
+3.2+%2F+%28+8+%2B+24+%29+=+.1+
+3.2+%2F+32+=+.1+
+3.2+=+3.2+
OK


Surface-area/720548: I am trying to find the perimeter of a back yard that has a length of 18x+2 and a width of 14x+1 but cannot figure out what the variable is for. Can you please help?
Thank you
1 solutions

Answer 441882 by josmiceli(9819) About Me  on 2013-02-28 23:56:35 (Show Source):
You can put this solution on YOUR website!
You don't have to know that. There is
no reason for it. Just add the 2 long
sides and the 2 short sides
+2%2A%2818x+%2B+2%29+%2B+2%2A%2814x+%2B+1+%29+
+36x+%2B+4+%2B+28x+%2B+2+
+64x+%2B+6+


Money_Word_Problems/720588: how much money would you have to accumulate in an investment in order the the yearly interest paid (simple) is equal to $70000 in the investment pays 5.9%
1 solutions

Answer 441881 by josmiceli(9819) About Me  on 2013-02-28 23:51:40 (Show Source):
You can put this solution on YOUR website!
Let +x+ = amount in investment
+.059x+=+70000+
+x+=+70000+%2F+.059+
+x+=+1186440.6+
The investment is $1,186,440.60


Money_Word_Problems/720571: An engine repair cost a truck owner $1,406 in parts and labor. If the parts were $670 and the mechanic charged $46 per hour, how many hours did the repair take?
1 solutions

Answer 441880 by josmiceli(9819) About Me  on 2013-02-28 23:46:56 (Show Source):
You can put this solution on YOUR website!
$1,406 in parts and labor
Let +t+ = hours of labor
+46t+%2B+670+=+1406+
+46t+=+1406+-+670+
+46t+=+736+
+t+=+16+
The repair took 16 hrs


percentage/720585: If you know 70% is 235 how do you find the other 30%
1 solutions

Answer 441879 by josmiceli(9819) About Me  on 2013-02-28 23:41:06 (Show Source):
You can put this solution on YOUR website!
One way is the subtract 70% of 235 from 235
+235+-+.7%2A235+
+235+-+164.5+=+70.5+


Travel_Word_Problems/720576: Charles was racing his remote control car this past weekend. The track is 1/4 mile long. His car averages 10 mph. How long did it take him to complete 20 laps around the track?
1 solutions

Answer 441878 by josmiceli(9819) About Me  on 2013-02-28 23:32:06 (Show Source):
You can put this solution on YOUR website!
+d+=+r%2At+
+.25+=+10t+
+t+=+.025+ hrs
This is the time to complete 1 lap
+20%2A.025+=+.5+
It takes a half hour to complete 20 laps


Miscellaneous_Word_Problems/720584: Find an equation for the graph (-2,4) and (0,-2)
1 solutions

Answer 441877 by josmiceli(9819) About Me  on 2013-02-28 23:27:36 (Show Source):
You can put this solution on YOUR website!
( -2,4 )
( 0,-2 )
Use the general point-slope formula
+%28+y+-%28-2%29+%29+%2F+%28+x+-+0+%29+=+%28+4+-%28-2%29+%29+%2F+%28+-2+-+0+%29+
+%28+y+%2B+2+%29+%2F+x+=+6+%2F+%28-2%29+
+y+%2B+2+=+x%2A%28-3%29+
+y+=+-3x+-+2+
---------------
check:
( -2,4 )
+y+=+-3x+-+2+
+4+=+-3%2A%28-2%29+-+2+
+4+=+6+-+2+
+4+=+4+
----------
( 0,-2 )
+-2+=+-3%2A0+-+2+
+-2+=+-2+
OK


Word_Problems_With_Coins/720582: The total value of the quarters and dimes in a coin bank is $8.90. If the quarters were dimes and the
dimes were quarters, the total value of the coins would be $8.60. Find the number of quarters in the
bank.
1 solutions

Answer 441876 by josmiceli(9819) About Me  on 2013-02-28 23:18:03 (Show Source):
You can put this solution on YOUR website!
Let +d+ = the number of dimes
Let +q+ = the number of quarters
given:
(1) +10d+%2B+25q+=+890+ ( in cents )
(2) +10q+%2B+25d+=++860+
-----------------------
Rewrite the equations
(1) +2d+%2B+5q+=+178+
(2) +5d+%2B+2q+=+172+
---------------------
Multiply both sides of (1) by
+5+ and both sides of (2)
by +2+ then subtract (2) from (1)
------------------------------
(1) +10d+%2B+25q+=+890+
(2) +-10d+-4q+=+-344+
+21q+=+546+
+q+=+26+
and
(1) +2d+%2B+5q+=+178+
(1) +2d+%2B+5%2A26+=+178+
(1) +2d+=+178+-+130+
(1) +2d+=+48+
(1) +d+=+24+
The number of dimes in the bank is 24
The number of quarters in the bank is 26
check:
(2) +10q+%2B+25d+=++860+
(2) +10%2A26+%2B+25%2A24+=+860+
(2) +260+%2B+600+=+860+
(2) +860+=+860+
OK



Age_Word_Problems/720491: If Jack adds his current age to the age he will be next year on this date, the sum is 17 years. How old will Jack be 6 years from today?
1 solutions

Answer 441854 by josmiceli(9819) About Me  on 2013-02-28 21:30:02 (Show Source):
You can put this solution on YOUR website!
Let +a+ = his current age
+a+%2B+1+ = his age 1 year from now
given:
+a+%2B+a+%2B+1+=+17+
+2a+=+16+
+a+=+8+
and
+a+%2B+6+=+8+%2B+6+
+a+%2B+6++=+14+
Jack will be 14 in 6 years


Linear_Equations_And_Systems_Word_Problems/720504: The largest box of popcorn in the world held a volume of 880 ft3 of popcorn. It took about six hours to fill the box. Find the rate per minute.
1 solutions

Answer 441851 by josmiceli(9819) About Me  on 2013-02-28 21:24:51 (Show Source):
You can put this solution on YOUR website!
In just units:
( ft3 / hr ) x ( hr / min ) = ft3 / min
+%28+880+%2F+6+%29%2A%28+1+%2F+60+%29+=+2.444+
The rate per minute is 2.444 ft3/min


Travel_Word_Problems/720508: Will you please help me answer this question none of my friends or parents know what to do, I could really use your help.
Here is the question:
flying with the wind a plane went 135 mph. Flying into the same wind the plane only went 93 mph. Find the speed of the wind and the speed of the plane in still air.
1 solutions

Answer 441846 by josmiceli(9819) About Me  on 2013-02-28 21:15:48 (Show Source):
You can put this solution on YOUR website!
Let +p+ = the speed of the plane in still air
Let +w+ = the speed of the wind
+p+%2B+w+ = the plane's speed flying with the wind
+p+-+w+ = the plane's speed flying into the wind
-------------------------------------------
given:
(1) +p+%2B+w+=+135+ mi/hr
92) +p+-+w+=+93+ mi/hr
Now add the equations
+2p+=+228+
+p+=+114+
Plug this value back into (1) or (2)
(1) +114+%2B+w+=+135+
(1) +w+=+21+
The speed of the plane in still air is 114 mi/hr
The speed of the wind is 21 mi/hr


test/720496: 235 is 15% of what?
1 solutions

Answer 441840 by josmiceli(9819) About Me  on 2013-02-28 20:55:54 (Show Source):


logarithm/720493: 7log(base7)4=x
i can get to 7^x=4^7 but i'm lost after that!
(not allowed to use calculators)
1 solutions

Answer 441839 by josmiceli(9819) About Me  on 2013-02-28 20:53:58 (Show Source):
You can put this solution on YOUR website!
+7%2Alog%28+7%2C4+%29+=+x+
+log%28+7%2C4+%29+=+x%2F7+
+7%5E%28x%2F7%29+=+4+
+%28+7%5Ex%29%5E%281%2F7%29+=+4+
Raise both sides to the 7th power
+7%5Ex+=+16384+
take the log of both sides
+x%2Alog%287%29+=+log%28+16384+%29+
+x+=+log%28+16384+%29+%2F+log%28+7+%29+


Rational-functions/720469: 6. A ball is thrown vertically upward with an initial velocity of 48 feet per second. The ball started from a height of 8 feet off the ground.
a. At what time will the rocket reach the maximum height? ______________
b. What is the maximum height the ball will reach? _______________
d. Where will the ball be after three seconds? _____________
e. What is the equation for the axis of symmetry? ________________________


1 solutions

Answer 441834 by josmiceli(9819) About Me  on 2013-02-28 20:25:04 (Show Source):
You can put this solution on YOUR website!
The effect of gravity pulling down is +-16t%5E2+ ft/sec2
The effect of upward initial velocity is +48t+ ft/sec
The hight off the ground adds +8+ ft
---------------------------------
The equation is +h+=+-16t%5E2+%2B+48t+%2B+8+
(a) The maximum height is at t+=++-b%2F%282a%29+ for
a parabola ( which this is ), when the form of the
equation is +h+=+at%5E2+%2B+b%2At+%2B+c+
+a+=+-16+
+b+=+48+
+-b%2F%282a%29+=+-48%2F%282%2A%28-16%29%29+
+-b%2F%282a%29+=+1.5+
So, at t = 1.5 sec, the height is a maximum
-------------------
(b)
Plug +t+=+1.5+ back into the equation to find h
+h%5Bmax%5D+=+-16%2A1.5%5E2+%2B+48%2A1.5+%2B+8+
+h%5Bmax%5D+=+-36+%2B+72+%2B+8+
+h%5Bmax%5D+=+44+
The max height is 44 ft
--------------------
(d)
In 3 sec, the ball will be
+h+=+-16t%5E2+%2B+48t+%2B+8+
+h+=+-16%2A3%5E2+%2B+48%2A3+%2B+8+
+h+=+-144+%2B+144+%2B+8+
In 3 sec, the ball will be 8 ft off the ground again
---------------------
(e)
The axis of symmetry is a vertical line, and every
point on that line has the same x-value, so
the equation for this line is +x+=+1.5+
Here's the plot of the equation:
+graph%28+400%2C+400%2C+-1%2C+5%2C+-5%2C+50%2C+-16x%5E2+%2B+48x+%2B+8+%29+






Rate-of-work-word-problems/720385: heather can rake all the leaves in the yard in 4 hours, Beth can do it in 6. How long would it take them to do the yard together?
1 solutions

Answer 441806 by josmiceli(9819) About Me  on 2013-02-28 18:12:24 (Show Source):
You can put this solution on YOUR website!
Add their rates of raking
Heather's rate:
( 1 yard ) / ( 4 hrs )
Beth's rate
( 1 yard ) / ( 6 hrs )
Rate raking together:
( 1 yard ) / ( t hrs )
-----------------
+1%2F4+%2B+1%2F6+=+1%2Ft+
Multiply both sides y +12t+
+3t+%2B+2t+=+12+
+5t+=+12+
+t+=+2.4+ hrs
+.4%2A60+=+24+
Together, they can rake the yard in 2 hrs 24 min
----------------
check:
+1%2F4+%2B+1%2F6+=+1%2Ft+
+.25+%2B+.1666+=+1%2F2.4+
+.25+%2B+.16666+=+.41666+
+.41666+=+.41666+
OK


Linear_Equations_And_Systems_Word_Problems/720374: its costs $120 to manufacture 2 bicycles and $160 to manufacture 4 bicycles. if the number of bicycles is the x- coordinate, and the amount of money is the y- coordinate, draw a graph of the line that would represent the relation between the number of bicycles and the cost to manufacture them assume it is a linear relationship
1 solutions

Answer 441803 by josmiceli(9819) About Me  on 2013-02-28 18:00:32 (Show Source):
You can put this solution on YOUR website!
Plot +C+ on the vertical axis
Plot +n+ on the horizontal axis
You are given the points
( 2,120 )
( 4,160 )
-------
+%28+C+-+120+%29+%2F+%28+n+-+2+%29+=+%28+160+-+120+%29+%2F+%28+4+-+2+%29+
+%28+C+-+120+%29+%2F+%28+n+-+2+%29+=+40+%2F+2+
+%28+C+-+120+%29+%2F+%28+n+-+2+%29+=+20+
+C+-+120+=+20%2A%28+n+-+2+%29+
+C+-+120+=+20n+-+40+
+C+=+20n+%2B+80+
-----------------
check:
Does the line go through ( 2,120) ?
+120+=+20%2A2+%2B+80+
+120+=+120+
Does the line go through (4,160) ?
+160+=+20%2A4+%2B+80+
+160+=+160+
OK


Radicals/720371: Please help us solve:
9^(2x+3)=2187
Keep getting negative number.
Thanks
Pat
1 solutions

Answer 441793 by josmiceli(9819) About Me  on 2013-02-28 17:46:41 (Show Source):
You can put this solution on YOUR website!
+9%5E%28+2x+%2B+3+%29+=+2187+
+9%5E%28+2x+%2B+3+%29+=+3%5E7+
+%283%5E2%29%5E%28+2x+%2B+3+%29+=+3%5E7+
+3%5E%28+2%2A%28+2x+%2B+3+%29+%29+=+3%5E7+
+3%5E%28+4x+%2B+6+%29+=+3%5E7+
The exponents must be the same on both sides
+4x+%2B+6+=+7+
+4x+=+1+
+x+=+1%2F4+
-----------
check:
+9%5E%28+2x+%2B+3+%29+=+2187+
+9%5E%28+2%2A%281%2F4%29+%2B+3+%29+=+2187+
+9%5E%28+1%2F2+%2B+3+%29+=+2187+
+9%5E%28+7%2F2+%29+=+2187+
+%289%5E%281%2F2%29%29%5E7+=+2187+
+3%5E7+=+2187+
+3%5E7+=+3%5E7+
OK


Volume/720366: How to find at least two new dimensions of the new box that's 4"by12"by8" that both have volumes 20% more than 384. Please help, so lost.
1 solutions

Answer 441786 by josmiceli(9819) About Me  on 2013-02-28 17:34:52 (Show Source):
You can put this solution on YOUR website!
That's a confusing question.
+4%2A12%2A8+=+384+
So, I guess they want 2 different boxes whose
volumes are 20% more than the given box
+384+%2B+.2%2A384+=+1.2%2A384+
+1.2%2A384+=+460.8+
-------------------
I think the thing to realize here is that if you
multiply any one of the 3 dimensions of the
original box by +1.2+, you will get a
volume that is 20% larger, so
+8%2A1.2+=+9.6+
4 x 12 x 9.6 is a possible box
-------------------------
+12%2A1.2+=+14.4+
4 x 14.4 x 8 is a possible box
-------------------------
+4%2A1.2+-+4.8+
4.8 x 12 x 8 is a possible box
--------------------------
Note all 3 give volume = 460.8 in3



Trigonometry-basics/720359: find the exact value of: cos pi/3 + sin pi/2 question 2: 4cos60(degrees) + 3tan pi/3

1 solutions

Answer 441782 by josmiceli(9819) About Me  on 2013-02-28 17:21:49 (Show Source):
You can put this solution on YOUR website!
I tend to convert radians to degrees so I can
visualize the angle.
+pi%2F3+%7B%7B%7B+radians+=+%7B%7B%7B+180%2F3+ degrees
+pi%2F3+ radians = +60+ degrees
----------------------------------
+pi%2F2+ radians = +180%2F2+ degrees
+pi%2F2+ radians = +90+ degrees
---------------------------------
(1)
I'll do the conversions to degrees:
+cos%28+60+%29+%2B+sin%28+90+%29+
+1%2F2+%2B+1+=+3%2F2+
(2)
+4%2Acos%28+60+%29+%2B+3%2Atan%28+60+%29+
+4%2A%281%2F2%29+%2B+3%2A%28+sqrt%283%29%2F1+%29+
+2+%2B+3%2Asqrt%283%29+



Radicals/720022: A bird leaves its nest in NY. it flies 6 km due east and 3 km due north how far is the bird from its nest. I dont know if this is a radical the unit we were studying is radical applications. Thank you
1 solutions

Answer 441630 by josmiceli(9819) About Me  on 2013-02-27 22:01:05 (Show Source):
You can put this solution on YOUR website!
The bird's path form a right triangle
Use the Pythagorean theorem
+d%5E2+=+6%5E2+%2B+3%5E2+
+d%5E2+=+36+%2B+9+
+d%5E2+=+45+
+d+=+sqrt%2845%29+
+d+=+3%2Asqrt%285%29+
+d+=+3%2A2.2361+
+d+=+6.7082+
The bird is 6.7082 km from it's nest


Money_Word_Problems/720024: Jordan invested $600 in a savings account. The interest rate is 6% per year. Find the simple interest earned in 3 years. Then find the total of principal plus interest
1 solutions

Answer 441628 by josmiceli(9819) About Me  on 2013-02-27 21:56:22 (Show Source):
You can put this solution on YOUR website!
+.06%2A600+=+36+
+3%2A36+=+108+
In 3 yrs $108 in interest is earned
Principle + interest = $708