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: 9678 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, >>Next

Linear-equations/568784: How do I figure out how to find the slope of the line containing the following points of (5/6,-2) and (-1/3, -1/3)?
1 solutions

Answer 367128 by josmiceli(9680) About Me  on 2012-02-06 20:43:46 (Show Source):
You can put this solution on YOUR website!
slope = ( change in y ) / ( change in x )
( 5/6, -2 ) and ( -1/3, -1/3 )
slope = +%28+-1%2F3+-%28-2%29+%29+%2F+%28+-1%2F3+-+5%2F6+%29+
-----------------------
+%28+-1%2F3+%2B+2+%29+%2F+%28+-7%2F6+%29+
----------------------
+%285%2F3%29+%2F+%28+-7%2F6+%29+
----------------
+%28+10%2F6+%29+%2F+%28+-7%2F6+%29+
-------------------
+-%2810%2F7%29+


Word_Problems_With_Coins/568778: What is the FEWEST number of coins you can use to make $0.96?
1 solutions

Answer 367125 by josmiceli(9680) About Me  on 2012-02-06 20:30:26 (Show Source):
You can put this solution on YOUR website!
3 quarters = .75
2 dimes = .20
1 cent = .01
------------
total = .96 with 6 coins
If 50 cent coins are allowed, then it's 5 coins


Linear-systems/568770: How do I solve:
y=x^3-2x^2+x-1
y=-x^2+3x-1
I substituted y=-x^2+3x-1 -x^2+3x-1=x^3-2x^2+x-1
0=x^3-x^2-2x
Not sure what to do next
1 solutions

Answer 367124 by josmiceli(9680) About Me  on 2012-02-06 20:21:58 (Show Source):
You can put this solution on YOUR website!
+y+=+x%5E3+-+2x%5E2+%2B+x+-+1+
+y+=+-x%5E2+%2B+3x+-+1+
By substitution:
+x%5E3+-+2x%5E2+%2B+x+-+1+=+-x%5E2+%2B+3x+-+1+
Add 1 to both sides
+x%5E3+-+2x%5E2+%2B+x++=+-x%5E2+%2B+3x++
+x%5E3+-+x%5E2+-+2x+=+0+
Factor out +x+
+x%2A%28+x%5E2+-+x+-+2+%29+
The solutions are:
+x+=+0+
+x%5E2+-+x+-+2+=+0+
+%28+x+-+2+%29%2A%28+x+%2B+1+%29+=+0+
+x+=+2+
+x+=+-1+
You can verify these by plugging them
back into +x%5E3+-+x%5E2+-+2x+=+0+




Travel_Word_Problems/568764: Suppose your car gets 28 miles per gallon of gasoline, and you are driving at 55 miles per hour. Find the amount of gas used in one hour.
1 solutions

Answer 367118 by josmiceli(9680) About Me  on 2012-02-06 20:08:01 (Show Source):
You can put this solution on YOUR website!
In terms of units:
( miles / hour ) / ( miles / gallon ) = gallons / hour
given:
+55+%2F+28+=+1.964+
1.964 gallons of gas are used in 1 hour


Miscellaneous_Word_Problems/568285: When Bert and Ernie merged their automobile dealerships, Bert had 10 more cars than Ernie. While 36% of Ernie's stock consisted of new cars, only 25% of Bert's stock consisted of new cars. If they had 33 new cars on the lot after the merger, then how many cars did each one have before the merger?
1 solutions

Answer 366897 by josmiceli(9680) About Me  on 2012-02-05 23:29:01 (Show Source):
You can put this solution on YOUR website!
Let +b+ = number of cars Bert had
Let +e+ = number of cars Ernie had
given:
(1) +b+=+e+%2B+10+
(2) +.25b+%2B+.36e+=+33+
---------------------
(2) +25b+%2B+36e+=+3300+
Substitute (1) into (2)
(2) +25%2A%28+e+%2B+10+%29+%2B+36e+=+3300+
(2) +25e+%2B+250+%2B+36e+=+3300+
(2) +61e+=+3050+
(2) +e+=+50+
and
(1) +b+=+e+%2B+10+
(1) +b+=+50+%2B+10+
(1) +b+=+60+
Bert had 60 cars
Ernie had 50 cars
check answer:
(2) +.25%2A60+%2B+.36%2A50+=+33+
(2) +15+%2B+18+=+33+
(2) +33+=+33+
OK


Numbers_Word_Problems/567957: find the triple of consecutive integers such that 11 times the largest of the integers is 46 more than the product of the other two
1 solutions

Answer 366822 by josmiceli(9680) About Me  on 2012-02-05 11:04:13 (Show Source):
You can put this solution on YOUR website!
Call the integers +n+, +n%2B1+, and +n%2B2+
given:
+11%2A%28+n%2B2+%29+=+n%2A%28+n%2B1+%29+%2B+46+
+11n+%2B+22+=+n%5E2+%2B+n+%2B+46+
+n%5E2+-+10n+%2B+24+=+0+
complete the square:
+n%5E2+-+10n+%2B+%28-10%2F2%29%5E2+=+-24+%2B+%28-10%2F2%29%5E2+
+%28+n+-+5+%29%5E2+=+-24+%2B+25+
+n+-+5+=+1+
+n+=+6+
also,
+n+-+5+=+-1+
+n+=+4+
------------
If the numbers are:
+n+=+6+
+n+%2B1+=+7+
+n+%2B+2+=+8+
+11%2A%28+n%2B2+%29+=+n%2A%28+n%2B1+%29+%2B+46+
+11%2A8+=+6%2A7+%2B+46+
+88+=+42+%2B+46+
+88+=+88+
OK
If the numbers are:
+n+=+4+
+n+%2B+1+=+5+
+n+%2B+2+=+6+
+11%2A%28+n%2B2+%29+=+n%2A%28+n%2B1+%29+%2B+46+
+11%2A6+=+4%2A5+%2B+46+
+66+=+20+%2B+46+
+66+=+66+
OK
The consecutive integers can be:
6,7, and 8
or
4,5, and 6


Miscellaneous_Word_Problems/567917: A worker was paid $4.50 per hour for a 40-hour week. The worker was paid an additional $1.50 per hour for each hour over 40 hours per week.
How much did the worker earn in 3 weeks if he worked 43 hours the first week, 42 hours the second week, and 45 hours the third week?
1 solutions

Answer 366819 by josmiceli(9680) About Me  on 2012-02-05 10:52:07 (Show Source):
You can put this solution on YOUR website!
The worker's overtime was +3+%2B+2+%2B+5+=+10+ hrs for 3 weeks
The worker's regular time was +40%2A3+=+120+ hrs
+10%2A%28+4.5+%2B+1.5+%29+=+60+
+120%2A4.5+=+540+
+60+%2B+540+=+600+
The worker earned $600 for 3 weeks


Circles/567951: please help :
the measure of a central angle of a sector is 36 degrees. the arc length of the sector is 4pi cm. what is the radius of the circle.
1 solutions

Answer 366818 by josmiceli(9680) About Me  on 2012-02-05 10:45:53 (Show Source):
You can put this solution on YOUR website!
+36+ degrees is +36%2F360+=+1%2F10+ of a full circle
Let +C+ = circumference
The arc length is +4%2Api+ cm
+4%2Api+=+%281%2F10%29%2AC+
+C+=+40%2Api+
The formula is:
+C+=+2%2Api%2Ar+
+40%2Api+=+2%2Api%2Ar+
+r+=+%28+40%2Api+%29+%2F+%28+2%2Api+%29+
+r+=+20+ cm


Travel_Word_Problems/567816: the train covers 90km in uniform speed.if speed is raised 15km/hr then train covers distance in half hour less.find the original speed.
1 solutions

Answer 366739 by josmiceli(9680) About Me  on 2012-02-04 23:12:43 (Show Source):
You can put this solution on YOUR website!
Let +s+ = original speed in km/hr
Let +t+ = time in hrs to cover +90+ km at speed +s+
given:
(1) +90+=+s%2At+
(2) +90+=+%28+s+%2B+15+%29%2A%28+t+-+.5+%29+
------------------------
(1) +t+=+90%2Fs+
Substitute (1) into (2)
(2) +90+=+s%2At+%2B+15t+-+.5s+-+7.5+
(2) +90+=+s%2A%2890%2Fs%29++%2B+15%2A%2890%2Fs%29+-+.5s+-+7.5+
(2) +90+=+90+%2B+1350%2Fs+-+.5s+-+7.5+
(2) +0+=+1350%2Fs+-.5s++-+7.5+
(2) +1350%2Fs+=+.5s+%2B+7.5+
(2) +1350+=+.5s%5E2+%2B+7.5s+
(2) +5s%5E2+%2B+75s+-+13500+=+0+
(2) +s%5E2+%2B+15s+-+2700+=+0+
Use quadratic formula
+s+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+1+
+b+=+15+
+c+=+-2700+
+s+=+%28+-15+%2B-+sqrt%28+15%5E2+-+4%2A1%2A%28-2700%29+%29%29%2F%282%2A1%29+
+s+=+%28+-15+%2B-+sqrt%28+225+%2B+10800+%29%29+%2F+2+
+s+=+%28+-15+%2B-+sqrt%28+11025+%29%29+%2F+2+ ( I can't use the negative square root )
+s+=+%28+-15+%2B+105+%29+%2F+2+
+s+=+90%2F2+
+s+=+45+
The original speed is 45 km/hr
check answer:
(1) +90+=+s%2At+
(1) +90+=+45t+
(1) +t+=+2+ hrs
and
(2) +90+=+%28+s+%2B+15+%29%2A%28+t+-+.5+%29+
(2) +90+=+%28+45+%2B+15+%29%2A%28+2+-+.5+%29+
(2) +90+=+60%2A1.5+
(2) +90+=+90+
OK


Problems-with-consecutive-odd-even-integers/567750: The sum of three consecutive even integers is 234. what are the integers?
1 solutions

Answer 366677 by josmiceli(9680) About Me  on 2012-02-04 17:49:51 (Show Source):
You can put this solution on YOUR website!
Let the integers be +n+, +n+%2B+2+, and +n+%2B+4+
given:
+n+%2B+n+%2B+2+%2B+n+%2B+4+=+234+
+3n+%2B+6+=+234+
+3n+=+228+
+n+=+76+
+n+%2B+2+=+78+
+n+%2B+4+=+80+
The numbers are 76, 78, and 80


Linear-equations/567748: Line A passes through the points (2k+3,4k-6) and (-2,16). Find the value of k, if line A has a slope of 0.
1 solutions

Answer 366676 by josmiceli(9680) About Me  on 2012-02-04 17:44:48 (Show Source):
You can put this solution on YOUR website!
(2k+3,4k-6) and (-2,16)
slope = ( change in y ) / ( change in x )
given:
slope = +0+
change in y = +0+
change in y = +16+-+%28+4k+-+6+%29+
+16+-+%28+4k+-+6+%29+=+0+
+16+-+4k+%2B+6+=+0+
+4k+=+22+
+k+=+11%2F2+
check answer:
slope = +%28+16+-+%28+4k+-+6+%29+%29+%2F+%28+-2+-+%28+2k+%2B+3+%29+%29+
slope = +%28+22+-+4k+%29+%2F+%28+-5+-+2k+%29+
slope = +%28+22+-+4%2A%2811%2F2%29+%29+%2F+%28-5+-+2%2A%2811%2F2%29+%29+
slope = +0+%2F+%28-16%29+=+0+
OK


Geometric_formulas/567568: photocopiers can reduce or enlarged an item being copied. the scale factor of the copy to the original is expressed as a percent. if you want the original to be one fourth the side of the copy, at what percent do you set the copier?
1 solutions

Answer 366617 by josmiceli(9680) About Me  on 2012-02-04 03:46:32 (Show Source):
You can put this solution on YOUR website!
Note that " percent " means " per one hundred ",
so "x" percent is +x%2F100+
given:
+x%2F100+=+1%2F4+
Multiply both sides by +400+
+4x+=+100+
+x+=+25+
se the copier to 25%


Age_Word_Problems/567574: The sum of the digits of a two digit number is 9. If the digits are reversed, the number formed bears the ratio 3:8 to the original number. Find the original number (Ans. 77)
1 solutions

Answer 366616 by josmiceli(9680) About Me  on 2012-02-04 03:39:25 (Show Source):
You can put this solution on YOUR website!
let the tens digit = +a+
Let the units digit = +b+
The actual number is +10a+%2B+b+
The number with the digits reversed is +10b+%2B+a+
given:
(1) +a+%2B+b+=+9+
(2) +%28+10b+%2B+a+%29+%2F+%28+10a+%2B+b+%29+=+3%2F8+
------------
Multiply both sides of (2) by +8%2A%28+10a+%2B+b+%29+
(2) +8%2A%2810b+%2B+a%29+=+3%2A%28+10a+%2B+b+%29+
(2) +80b+%2B+8a+=+30a+%2B+3b+
(2) +22a+-+77b+=+0+
(2) +22a+=+77b+
(2) +a+=+%2877%2F22%29%2Ab+
(2) +a+=+%287%2F2%29%2Ab+
Substitute (2) into (1)
(1) +%287%2F2%29%2Ab+%2B+b+=+9+
(1) +7b+%2B+2b+=+18+
(1) +9b+=+18+
(1) +b+=+2+
and, since
(1) +a%2B+b+=+9+
(1) +a+%2B+2+=+9+
(1) +a+=+7+
The original number is 72
check answer:
(2) +%28+10b+%2B+a+%29+%2F+%28+10a+%2B+b+%29+=+3%2F8+
(2) +%28+10%2A2+%2B+7+%29+%2F+%28+10%2A7+%2B+2+%29+=+3%2F8+
(2) +27+%2F+72+=+3%2F8+
Multiply both sides by +72+
(2) +27+=+3%2A9+
(2) +27+=+27+
OK
Note that the answer +77+ is impossible,
since the digits have to add up to 9


Probability-and-statistics/567576: what will you addto 5/8 to make it equal to 1?
PLS.....ANSwer..????I NEED YOUR"E HELP
1 solutions

Answer 366615 by josmiceli(9680) About Me  on 2012-02-04 03:20:45 (Show Source):
You can put this solution on YOUR website!
If you look at the sentence:
{ what ) ( added to ) 5/8 ( equals ) 1 ?
Now just rewrite it
+x+ + +5%2F8+ = +1+
+x+%2B+5%2F8+=+1+
Subtract +5%2F8+ from both sides
+x+=+1+-+5%2F8+
+x+=+8%2F8+-+5%2F8+
+x+=+3%2F8+
So, if you plug this back into the sentence itself,
3/8 ( added to ) 5/8 ( equals ) 1
-------------------
Hope this helps


Angles/567470: At what time between 7pm and 8pm will the minute hand be 90 degrees behind the hour hand?
1 solutions

Answer 366550 by josmiceli(9680) About Me  on 2012-02-03 19:04:09 (Show Source):
You can put this solution on YOUR website!
Each hour mark on the clock is +5%2F60+=+1%2F12+ of
a +360+ degree circle apart. That is +%281%2F12%29%2A360+=+30+ degrees
At 7 pm, the minute hand and hour hand are
+7%2A30+=+210+ degrees apart
The minute hand is moving at the rate of +360+%2F+60+=+6+ degrees/min
The hour hand is moving at the rate of +30%2F60+=+1%2F2+ degree/min
------------------
Let +d%5B1%5D+ = the degrees that the minute hand travels until it makes
an angle of +90+ degrees with the hour hand
Let +d%5B2%5D+ = the degrees that the hour hand travels until it makes
an angle of +90+ degrees with the minute hand
Let +t+ = time in minutes until they are +90+ degrees apart
------------------
(1) +210+%2B+d%5B2%5D+-+d%5B1%5D+=+90+
(2) +6t++=+d%5B1%5D+
(3) +%281%2F2%29%2At+=+d%5B2%5D+
------------------
This is 3 equations and 3 unknowns, so it's solvable
Substitute (2) and (3) into (1)
(1) +210+%2B+%281%2F2%29%2At+-+6t+=+90+
(1) +420+%2B+t+-+12t+=+180+
(1) +-11t+=+180+-+420+
(1) +11t+=+240+
(1) +t+=+21.818+ min
+.818%2A60+=+49.09+ sec
The hands will be 90 degrees apart at 21 min and 49 sec past 7 PM
hope I got it


Travel_Word_Problems/567474: The Hopewells are moving across the country. Mr. Hopewell leaves 3.5 hours before Mrs. Hopewell. If he averages 40 mph and she averages 50 mph, how long wil it take Mrs. Hopewell to overtake Mr. Hopewell?
1 solutions

Answer 366543 by josmiceli(9680) About Me  on 2012-02-03 18:34:53 (Show Source):
You can put this solution on YOUR website!
How much of a head start does Mr. H get in +3.5+ hrs ?
+d%5B1%5D+=+40%2A3.5+
+d%5B1%5D+=+140+
Start a stopwatch when Mrs. H leaves
They both will travel for the same time, +t+
Let +d+ = distance Mrs. H has to travel until they meet
Mrs. H's equation:
+d+=+50t+
Mr. Hl's equation:
+d+-+140+=+40t+
By substitution,
+50t+-+140+=+40t+
+10t+=+140+
+t+=+14+ hrs
It will take her 14 hrs to overtake him


Travel_Word_Problems/567478: A woman jogs for 2 km at 8 km/h and then walks for 2 km at 6 km/h. What is the average speed for the entire trip
1 solutions

Answer 366542 by josmiceli(9680) About Me  on 2012-02-03 18:22:17 (Show Source):
You can put this solution on YOUR website!
Average speed is ( total distance ) / ( total time )
+t%5B1%5D+=+2%2F8+
+t%5B1%5D+=+1%2F4+ hr
+t%5B2%5D+=+2%2F6+
+t%5B2%5D+=+1%2F3+ hr
ave speed = +%28+2+%2B+2+%29+%2F+%28+1%2F4+%2B+1%2F3+%29+
+4+%2F+%28+3%2F12+%2B+4%2F12+%29+
+4+%2F+%287%2F12%29+
+%2812%2F7%29%2A4+
+48%2F7+=+6.857+ km/hr
check answer:
ave speed = +%28+2+%2B+2+%29+%2F+%28+1%2F4+%2B+1%2F3+%29+
ave speed = +4+%2F+%28+.25+%2B+.333+%29+
ave speed = +4+%2F+.58333+
ave speed = +6.857+ km/hr




Mixture_Word_Problems/567479: Balsamic vinegar contains 5% acetic acid, so a 32-oz bottle of balsamic vinegar contains ounces of acetic acid.
1 solutions

Answer 366537 by josmiceli(9680) About Me  on 2012-02-03 18:02:07 (Show Source):


Rate-of-work-word-problems/567449: 4 painters can paint a house in 3 days, at this rate, how many houses can 6 painters paint in 6 days?
1 solutions

Answer 366530 by josmiceli(9680) About Me  on 2012-02-03 16:38:44 (Show Source):
You can put this solution on YOUR website!
If 4 painters can paint a house in 3 days, then
3 times as many painters can paint a house in
1/3 that time, so 12 painters can paint a house
in 1 day
------------
6 painters will take twice that time,
or 6 painters paint 1 house in 2 days
------------
In 6 days, the 6 painters can paint 3 times as many
houses, so in 6 days 6 painters can paint 3 houses


Coordinate-system/567425: find the midpoint for (-1/3,1/3) and (-7/3,-5/3)
1 solutions

Answer 366528 by josmiceli(9680) About Me  on 2012-02-03 16:10:13 (Show Source):
You can put this solution on YOUR website!
(-1/3,1/3) and (-7/3,-5/3)
First, find the midpoint of the x-coordinates
+%28+-7%2F3+%2B+%28-1%2F3%29+%29+%2F+2+
---------------------
+%28-8%2F3%29+%2F+2+
-------------
+-8%2F6+=+-4%2F3+
----------------
Then find the midpoint of the y-coordinates
+%28+-5%2F3+%2B+1%2F3+%29+%2F+2+
-------------------
+%28-4%2F3%29%2F2+
-----------
+-2%2F3+
--------
The midpoint is (-4/3, -2/3 )


Linear-equations/567435: Which is a parallel line to 3x-y=-9?
-6x-y=-9
-x+3y=-9
-6x+2y=-9
-6x-2y=-9
1 solutions

Answer 366524 by josmiceli(9680) About Me  on 2012-02-03 15:52:55 (Show Source):
You can put this solution on YOUR website!
Compare the slopes of the lines
First, put them all in the form
+y+=+m%2Ax+%2B+b+, where +m+
is the slope
--------------
(1)
+3x+-+y+=+-9+
+y+=+3x+%2B+9+
-------------
(2)
+-6x+-+y+=+-9+
+y+=+-6x+%2B+9+
-------------
(3)
+-x+%2B+3y+=+-9+
+3y+=+x+-+9+
+y+=+%281%2F3%29%2Ax+-+3+
-------------
(4)
+-6x+%2B+2y+=+-9+
+2y+=+6x+-+9+
+y+=+3x+-+9%2F2+
-------------
(5)
+-6x+-+2y+=+-9+
+2y+=+-6x+%2B+9+
+y+=+-3x+%2B+9%2F2+
-------------
The slope that matches the slope of
equation (1) is equation (4):
(1) +y+=+3x+%2B+9+
(4) +y+=+3x+-+9%2F2+
+m+=+3+ for both


Numbers_Word_Problems/567263: At 8:00P.M., there are 243 people in line for a ride at an amusepark. Every 12 minutes starting at 8PM., 42 people are able to enter the ride. a boy gets in line at 8:00 P.M. Will he get to ride before the ride shuts down at 9:00 P.M.? explain
1 solutions

Answer 366492 by josmiceli(9680) About Me  on 2012-02-03 05:33:44 (Show Source):
You can put this solution on YOUR website!
Since +12%2A5+=+60+, the groups of 42 people
will be able to get on 5 times starting at 8 PM
+5%2A42+=+210+, so 210 people can get on in
one hour, leaving the boy still in line with 33 people
when the ride shuts down


Mixture_Word_Problems/567250: how many liters of pure acid must grace add to four liters of a 10% acid solution to increase the strength to 80%
1 solutions

Answer 366491 by josmiceli(9680) About Me  on 2012-02-03 05:27:14 (Show Source):
You can put this solution on YOUR website!
Let +x+ = liters of pure acid to be added
+.1%2A4+=+.4+ liters of acid in 10% solution
---------------
+%28+x+%2B+.4+%29+%2F+%28+x+%2B+4+%29+=+.8+
+x+%2B+.4+=+.8%2A%28+x+%2B+4+%29+
+x+%2B+.4+=+.8x+%2B+3.2+
+.2x+=+3.2+-+.4+
+.2x+=+2.8+
+x+=+14+
14 liters of pure acid is needed
check:
+%28+x+%2B+.4+%29+%2F+%28+x+%2B+4+%29+=+.8+
+%28+14+%2B+.4+%29+%2F+%28+14+%2B+4+%29+=+.8+
+14.4+%2F+18+=+.8+
+14.4+=+.8%2A18+
+14.4+=+14.4+
OK


Travel_Word_Problems/567271: A car starts with the speed 60 km/hr from prayad at 3 p.m. After 1 hour a second car starts with the speed 80 km/hr on the same track to cross to the first car. After how many kms the second car wil meet the first?
1 solutions

Answer 366490 by josmiceli(9680) About Me  on 2012-02-03 05:18:39 (Show Source):
You can put this solution on YOUR website!
The 1st car gets a head start of +1+ hr
In +1+ hr, it travels +60%2A1+=+60+ km
Count time when the 2nd car leaves.
Let +t+ = time in hours until they meet
Let +d+ = distance 2nd car travels until they meet
-----------------
Equation for 2nd car:
+d+=+80t+
Equation for 1st car:
+d+-+60+=+60t+
--------------
By substitution:
+80t+-+60+=+60t+
+20t+=+60+
+t+=+3+
--------------
+d+=+80t+
+d+=+80%2A3+
+d+=+240+
When both cars have traveled 240 km,
they will meet


Numeric_Fractions/567164: what is 12 and 1/3 subtract 7 and 5/6
1 solutions

Answer 366442 by josmiceli(9680) About Me  on 2012-02-02 22:01:40 (Show Source):
You can put this solution on YOUR website!
First, +1%2F3+=+2%2F6+
+12+%2B+2%2F6+-+%28+7+%2B+5%2F6+%29+
+12+%2B+2%2F6+-+7+-+5%2F6+
+12+-+7+%2B+2%2F6+-+5%2F6+
+5+-+3%2F6+
note that +3%2F6+=+1%2F2+ so,
+5+-+1%2F2+=+4+%2B+1%2F2 answer


Linear_Equations_And_Systems_Word_Problems/567146: The height, h (in feet), of a falling object on Mars is given by h=-6t2+s , where t is the time in seconds and s is the initial height in feet. If an object were dropped from a height of 125 feet, how long would it take to travel half the distance to the ground?
1 solutions

Answer 366440 by josmiceli(9680) About Me  on 2012-02-02 21:30:01 (Show Source):
You can put this solution on YOUR website!
+h+=+-6t%5E2+%2B+s+
+s+=+125+ ft
find +t+ when +h+=+125%2F2+
+125%2F2+=+-6t%5E2+%2B+125+
+125+=+-12t%5E2+%2B+250+
+-12t%5E2+=+-125+
+t%5E2+=+10.41666+
+t+=+3.2275+ sec


Linear-systems/567119: Birdseed costs $0.59 a pound and sunflower seeds cost %0.89. Angela's pet store wishes to make a 40-pound mixture of birdseed and sunflower seeds that sells for $0.76 per pound. How many pounds of each type of seeds should she use?
Please help me solve this application problem for systems of linear equations!
1 solutions

Answer 366439 by josmiceli(9680) About Me  on 2012-02-02 21:12:55 (Show Source):
You can put this solution on YOUR website!
Let +a+ = pounds of birdseed needed
Let +b+ = pounds of sunflower seeds needed
given:
(1) +a+%2B+b+=+40+
(2) +%28+.59a+%2B+.89b+%29+%2F+40+=+.76+
---------------------------
(2) +.59a+%2B+.89b+=+.76%2A40+
(2) +.59a+%2B+.89b+=+30.4+
(2) +59a+%2B+89b+=+3040+
Multiply both sides of (1) by +59+
and subtract (1) from (2)
(2) +59a+%2B+89b+=+3040+
(1) +-59a+-+59b+=+-2360+
+30b+=+680+
+b+=+22.667+
and
(1) +a+%2B+22.667+=+40+
(1) +a+=+17.+333+
17 and 1/3 pounds of birdseed are needed
22 and 2/3 pounds of sunflower seed are needed
check answer:
(2) +%28+.59%2A17.333+%2B+.89%2A22.667+%29+%2F+40+=+.76+
(2) +%28+10.22666+%2B+20.17333+%29+%2F+40+=+.76+
(2) +30.40003+=+.76%2A40+
(2) +30.40003+=+30.4+
close enough, error due to rounding off


Numeric_Fractions/567103: 1 1/4 divided by a=5
I am trying to help my son with this and we can't figure it out. Will you please show all the work so we can do the rest of his homework from your example? THANK YOU!!!
1 solutions

Answer 366433 by josmiceli(9680) About Me  on 2012-02-02 20:39:17 (Show Source):
You can put this solution on YOUR website!
1 1/4 divided by 5
You can think of this as
+1%2F5+%2B+%28%281%2F4%29%2F5%29+
It's a little hard to imagine 1/4
divided into 5 equal parts, but if
you multiply the top and bottom
by +5+, like this:
+%285%2F5%29%2A%281%2F4%29+=+5%2F20+, the value
hasn't changed, and now you've got
+5%2F20+=+1%2F20+%2B+1%2F20+%2B+1%2F20+%2B+1%2F20+%2B+1%2F20+
and it's easy to divide by 5
+%285%2F20%29%2F5+=+1%2F20+
-------------------
So far I've got +1%2F5+%2B+1%2F20+
Multiply top and bottom of +1%2F5+ by +4+
+%284%2F4%29%2A%281%2F5%29+=+4%2F20+
Now I have +4%2F20+%2B+1%2F20+
+4%2F20+%2B+1%2F20+=+5%2F20+
Divide top and bottom by +5+
+%285%2F5%29+%2F+%2820%2F5%29+=+1%2F4+ answer
---------------------------
(5/5) and (4/4) are just +1+, so
multiplying by them doesn't change the rest


Age_Word_Problems/567094: Jon says: When I add 7 times my age 7 years from now to 11 times my age 11 years from now, I get 20 times my current age. How old will I be 5 years from now?
1 solutions

Answer 366432 by josmiceli(9680) About Me  on 2012-02-02 20:22:30 (Show Source):
You can put this solution on YOUR website!
Let +x+ = Jon's age now
+x+%2B+7+ = Jon's age 7 yrs from now
+x+%2B+11+ = Jon's age 11 yrs from now
+x+%2B+5+ = Jon's age 5 yrs from now
given:
+7%2A%28+x+%2B+7+%29+%2B+11%2A%28+x+%2B+11+%29+=+20x+
+7x+%2B+49+%2B+11x+%2B+121+=+20x+
+18x+%2B+170+=+20x+
+2x+=+170+
+x+=+85+
+x+%2B+5+=+90+
In 5 yrs I will be 90
check:
+7%2A%28+85+%2B+7+%29+%2B+11%2A%28+85+%2B+11+%29+=+20%2A85+
+7%2A85+%2B+49+%2B+11%2A85+%2B+121+=+20%2A85+
+20%2A85+-+18%2A85+=+121+%2B+49+
+2%2A85+=+170+
+170+=+170+
OK


Numbers_Word_Problems/566626: The sum of the digits of a two-digit number is 8. The number with the digits interchanged is 14 more than 8 times the unit digit of the original.What is the number?
1 solutions

Answer 366296 by josmiceli(9680) About Me  on 2012-02-02 03:31:36 (Show Source):
You can put this solution on YOUR website!
Let +a+ = the tens digit
Let +b+ = the units digit
The number is +10a+%2B+b+
given:
(1) +a+%2B+b+=+8+
The number with the digits interchanged is
+10b+%2B+a+
(2) +10b+%2B+a+=+8b+%2B+14+
(2) +a+%2B+10b+-+8b+=+14+
(2) +a+%2B+2b+=+14+
Subtract (1) from (2)
(2) +a+%2B+2b+=+14+
(1) +-a+-+b+=+-8+
+b+=+6+
and
(1) +a+%2B+b+=+8+
(1) +a+%2B+6+=+8+
(1) +a+=+8+-+6+
(1) +a+=+2+
The number is 26
check answer:
(2) +a+%2B+2b+=+14+
(2) +2+%2B+2%2A6+=+14+
(2) +2+%2B+12+=+14+
OK


Permutations/566618: Suppose that the format for license plates in a certain state is 2 letters followed by 4 numbers.
- How many different plates are there if the letters can be repeated but no two numbers can be the same?
- How many different plates can be made if repetitions of numbers and letters are allowed except that no plate can have four zeros?
Thanks!
1 solutions

Answer 366295 by josmiceli(9680) About Me  on 2012-02-02 03:19:23 (Show Source):
You can put this solution on YOUR website!
If the letters can be repeated but no two numbers can be the same
+26%2A26%2A10%2A9%2A8%2A7+=+3407040+
if repetitions of numbers and letters are allowed except no plate can have 4 zeros
+26%2A26%2A10%2A10%2A10%2A10+-+26%2A26+
+26%2A26%2A%2810000+-+1+%29+
+26%2A26%2A9999+=+6759324