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 'mananth'

mananth answered: 12270 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, >>Next

Exponents-negative-and-fractional/404773: Please help me solve this problem: (-10n)^2(-4n^3)3
1 solutions

Answer 286054 by mananth(12270) About Me  on 2011-02-05 20:44:23 (Show Source):
You can put this solution on YOUR website!
(-10n)^2(-4n^3)^3
%28-10n%29%5E2%28-4n%5E3%29%5E3
100n%5E2%2A-64n%5E9
-6400n%5E11


Systems-of-equations/404745: 3x+y=2
4y=12-12x
1 solutions

Answer 286053 by mananth(12270) About Me  on 2011-02-05 20:40:10 (Show Source):
You can put this solution on YOUR website!
3x+y=2.......(1)
4y=12-12x
4y+12x=12
/4
y+3x=3
multiply by -1
-y-3x=-3
add this to first equation
we get 0= -1
There is no solution to the system


Linear-equations/404717: (0,0) x = -3y - 12 find an equation of the line that passes through the given point and is perpendicular to the given line. write the equation in slope intercept form.
1 solutions

Answer 286052 by mananth(12270) About Me  on 2011-02-05 20:35:29 (Show Source):
You can put this solution on YOUR website!
(0,0) x = -3y - 12
x = -3y - 12
3y=-x-12
/3
y=-x/3 -4
compare with y= mx+b
m= slope = -1/3
..
The perpendicular line will have slope 3
..
since the line passes through(0,0) the y intercepr = -12. b=-12
y=3x-12 is the equation
...
graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Cy=-x%2F3-4%2Cy=3x-12%29%29


Miscellaneous_Word_Problems/404768: The cost of a bus excursion was $180. This amount was to have been shared equally by all those who said they wished to go. However, 6 people failed to show up so that those who did go each had to pay $1.50 more. How many people actually went on the trip?
I just want to know how to get started I do not need the actual answer.
1 solutions

Answer 286049 by mananth(12270) About Me  on 2011-02-05 20:21:56 (Show Source):
You can put this solution on YOUR website!
let x people decide to go initially
..
cost per person = 180/x
...
6 persons opt out . number which went = x-6
...
so amount to be paid = 180 /(x-6)
...
180/(x-6) -180/x = 1.5


Evaluation_Word_Problems/404769: The length of the first side of a triangle is twice the length of the second side, and the length of the third side is 5 more than the length of the second side. Express the perimeter of the triangle in terms of the length of its second side, and use this model to estimate the lengths of the three sides if the perimeter is to be 100 in.
1 solutions

Answer 286046 by mananth(12270) About Me  on 2011-02-05 20:17:33 (Show Source):
You can put this solution on YOUR website!
The length of the first side of a triangle is twice the length of the second side, and the length of the third side is 5 more than the length of the second side. Express the perimeter of the triangle in terms of the length of its second side, and use this model to estimate the lengths of the three sides if the perimeter is to be 100 in.
...
second side = x
first side= 2x
third side= x+5
...
x+2x+x+5======> 4x+5 = Perimeter
...
4x+5 =100
4x=95
/4
x=23.75 in
2x= 47.50 in
x+5 = 28.75 in


Travel_Word_Problems/404408: a passenger train leaves a train station four hours after a train leaves the same station. The freight train is traveling ten mph slower than the passenger train. Find the rate of the passenger train if the passenger train overtakes the fright train in 20 hours.
1 solutions

Answer 285882 by mananth(12270) About Me  on 2011-02-05 04:51:01 (Show Source):
You can put this solution on YOUR website!
a passenger train leaves a train station four hours after a train leaves the same station. The freight train is traveling ten mph slower than the passenger train. Find the rate of the passenger train if the passenger train overtakes the fright train in 20 hours.
..
Passenger train x mph
freight train x-10 mph
...
In fours hours freight train has traveled 4(x-10) hours
,..
Catch up distance = 4(x-10)
catch up speed = 10 mph
Time = distance / speed
4(x-10)/10= 20
4x-40=200
4x=240
x=60 mph.
Speed of passenger train = 60 mph


Linear-systems/404506: How would I graph the following system of inequalities?
y≥-1
x≥5
Thank you
1 solutions

Answer 285881 by mananth(12270) About Me  on 2011-02-05 04:41:33 (Show Source):


Polynomials-and-rational-expressions/404503: please help
which of the following binomials is a factor of 2n^2 - 18
n + 3
n^2 + 9
2n + 3
2n^2 + 9
1 solutions

Answer 285879 by mananth(12270) About Me  on 2011-02-05 04:36:42 (Show Source):
You can put this solution on YOUR website!
option 1 (n+3)
2(n^2-9)
2(n+3)(n-3)


Polynomials-and-rational-expressions/404528: The area of a rectangular athletic field is represented by the expression 28y^4 -21y^3 +56y^2 square meters. Write an algebraic expression to represent one possible set of dimensions (in the sense “length times width”) of the athletic field. Include correct units with your solution.
1 solutions

Answer 285878 by mananth(12270) About Me  on 2011-02-05 04:34:01 (Show Source):
You can put this solution on YOUR website!
28y^4 -21y^3 +56y^2
(7y^2)(4y^2-3y+8)= Area


Miscellaneous_Word_Problems/404529: thirty percent of a number is equals to twenty-five percent of 144.what is the unknown number?
1 solutions

Answer 285877 by mananth(12270) About Me  on 2011-02-05 04:29:27 (Show Source):
You can put this solution on YOUR website!
let the number be x
30% 0f x= 25% of 144
%2830%2F100%29+%2Ax=%2825%2F100%29+%2A144
x= (100*25*144)/100*30
x=120


Rectangles/404530: the area of a rectangle is 96 square centimeters. if the width of the rectangle is 4 centimeter less than its length, what are the dimension of the rectangle
1 solutions

Answer 285876 by mananth(12270) About Me  on 2011-02-05 04:24:11 (Show Source):
You can put this solution on YOUR website!
length= x
width = x-4
...
area = L*W
Area = x(x-4)=96
x^2-4x=96
x^2-4x-96=0
x^2-12x+8x-96=0
x(x-12)+8(x-12)=0
*x-12)(x+8)=0
So x= 12 cms===>length
width = 12-4=8 cm


Polynomials-and-rational-expressions/404426: The area of a rectangular swimming pool is given by 3x^2-2x-1ft^2 . One side length of the pool is given by 3x + 1 feet. What is an algebraic expression for the other side length of the pool? Simplify this, and include correct units as part of your answer.


1 solutions

Answer 285869 by mananth(12270) About Me  on 2011-02-05 01:18:20 (Show Source):
You can put this solution on YOUR website!
The area of a rectangular swimming pool is given by 3x^2-2x-1ft^2 . One side length of the pool is given by 3x + 1 feet. What is an algebraic expression for the other side length of the pool? Simplify this, and include correct units as part of your answer.

The area = 3x^2-2x-1ft^2 .
One side length= 3x + 1 feet.
Area = L*W
Area / Length = Width
%283x%5E2-2x-1%29%2F%283x%2B1%29=+width
%28%28x-1%29%283x%2B1%29%29%2F%283x%2B1%29=width
%28%28x-1%29%28cross%283x%2B1%29%29%29%2F%28cross%283x%2B1%29%29=width
Width = (x-1)feet


Coordinate-system/404446: Show that a square whose diagonal has length d has perimeter 2sqrt2d.
1 solutions

Answer 285868 by mananth(12270) About Me  on 2011-02-05 01:11:01 (Show Source):
You can put this solution on YOUR website!
diagonal = d
apply pythagoras theorem
Let the legs be x each
..
d^2= x^+x^2
d^2=2x^2
divide by 2
d^2/2= x^2
x=+sqrt%28d%5E2%2F2%29
x=d%2F%28sqrt%282%29%29
Perimeter = 4*length
Perimeter+=+4%2Ad%2F%28sqrt%282%29%29
Perimeter+=+2sqrt%282%29%2Ad


Linear-systems/404508: I need to solve the following system of equations
x+6y=9 (1)
x=7-6y (2)
What is the solution to the system?


Thank you
1 solutions

Answer 285866 by mananth(12270) About Me  on 2011-02-05 00:57:57 (Show Source):
You can put this solution on YOUR website!
x+6y=9 (1)
x=7-6y (2)
add 6y to both sides
x+6y=7... (2)
compare (1) & (2)
we get 9=7
...
There is no solution to this system





Linear-equations/404521: find the slope for (9,7) and (19,8)
1 solutions

Answer 285864 by mananth(12270) About Me  on 2011-02-05 00:51:35 (Show Source):
You can put this solution on YOUR website!
find the slope for (9,7) and (19,8)
slope m = (y2-y1)/(x2-x1)
m= (8-7)/(19-9)
m=1/10====> slope


Inequalities/404514: Please assist me with solving the inequality and also could you show me how you came up with the answer:
-18t-2<24
Thank you
1 solutions

Answer 285863 by mananth(12270) About Me  on 2011-02-05 00:49:58 (Show Source):
You can put this solution on YOUR website!
-18t-2<24
add +2 to both sides
-18t-2+2<24+2
-18t<26
divide by -2
-18t/-2 > 26/-2
Because you are dividing by a negative number
the sign reverses
9t>-13
divide by 9
t>-13/9


Pythagorean-theorem/404480: 10. A square has a 40-cm diagonal. How long is each side of the square? Round your answer to the nearest tenth of a centimeter. (1 point
1 solutions

Answer 285844 by mananth(12270) About Me  on 2011-02-04 22:08:54 (Show Source):
You can put this solution on YOUR website!
The legs and the diagonal form a right angle.
The diagonal is the hypotenuse.
apply Pythagoras theorem
..
Let l be one leg.
since it is a square the other leg is also l.
l^2+l^2= 40^2
2l^2=1600
l^2=800
l = sqrt (800)
l = 28.28
...
l= 28.3 cm


Travel_Word_Problems/404209: B is 50% faster than A. If A starts at 9 A.M. and B starts at 10 A.M. A travels at a speed of 50 km/hr.
If A and B are 300 kms apart, The time when they meet when they travel in opposite direction is ?
1 solutions

Answer 285675 by mananth(12270) About Me  on 2011-02-04 05:49:07 (Show Source):
You can put this solution on YOUR website!
A 50 km/h
...
50% of A = 25 km/h
...
B travels at 75km/h
..
B starts at 10 am.
A starts at 9 am
..
A travels 50 km in 1 hour
..
when B starts they are 300 -50 km apart.
=250km.
Speed together = 50+75 = 125 km/h
Time = distance /speed
Time =250/125
Time = 2hours to meet.
They meet at 12.00 noon


Geometry_proofs/404128: x-y=-1
3x+y=5
1 solutions

Answer 285664 by mananth(12270) About Me  on 2011-02-03 23:45:05 (Show Source):
You can put this solution on YOUR website!
x-y=-1.................1
3x+y=5.................2
...
add (1) & (2)
x+3x-y+y=-1+5
4x=4
/4
x=1
,,plug value of x in 1
x-y =-1
1-y=-1
y=1+1
y=2


Travel_Word_Problems/403742: Stephen left at 6:00am and traveled 470 miles at a rate of 55mph. About when will he arrive at his destination?
1 solutions

Answer 285453 by mananth(12270) About Me  on 2011-02-03 08:41:43 (Show Source):
You can put this solution on YOUR website!
+time+=+distance%2Fspeed
distance =470
speed = 55 mph
+t=+470%2F55
t = 8.54 hours
0.54*60 = minutes====> =32 minutes
time = 8 hours 32 minutes
reaching time = 2:32 pm


Money_Word_Problems/403690: Mary two student loans total $9000. One loan is at 5% simple interest and the other is at 6% simple interest. At the end of 1 yr, Mary owes $492 in interest. What is the amount of each loan?
1 solutions

Answer 285452 by mananth(12270) About Me  on 2011-02-03 08:36:23 (Show Source):
You can put this solution on YOUR website!
Mary two student loans total $9000. One loan is at 5% simple interest and the other is at 6% simple interest. At the end of 1 yr, Mary owes $492 in interest. What is the amount of each loan?
Mary two student loans total $9000.
5% simple interest------------$x
6% simple interest. -----------9000-x
$492 in interest.
..
5x+6(9000-x)=492*100
5x+54000-6x=49200
-x=-54000+49200
-x=-4800
x=$4800====> 5%
balance $4200 at 6%


Expressions-with-variables/403723: a sparrow flies to see a friend at a speed of 4km/h. his friend is out,so the sparrow immediately returns home at a speed of 5km/h. the complete journey took 54 minutes. how many far away does his friend Live?
1 solutions

Answer 285451 by mananth(12270) About Me  on 2011-02-03 08:30:01 (Show Source):
You can put this solution on YOUR website!

let distance be x km
while going to meet 4km/h
time taken = x/4
...
return speed = 5km/h
time = x/5
...
x/5 +x/4 = 54/60
(4x+5x)/20=54/60
9x=54*20/60
9x=18
/9
x= 2km====> distance friend lives


Graphs/403740: Use the five step to solve and show.
The area of a triangular section of a store cannot be more than 910 sq. ft. If the height of the triangular section is 52 ft, what should the base be?
1 solutions

Answer 285447 by mananth(12270) About Me  on 2011-02-03 08:25:24 (Show Source):
You can put this solution on YOUR website!
+area+%3C=+910+ft%5E2
Height = 52
..
Area of triangle = 1/2 * base * height
Area = 1/2*base*52
1/2*base*52<=910
26%2Abase%3C=910
base%3C=+910%2F26
base%3C=35


Graphs/403739: Use the five steps for problem solving to answer the following question. Show all work and solve.
Laura found $2.15 in quarters and nickles in the bottom of her purse. There were seven fewer quarters than nickles. How many nickles and quarters did she have?
1 solutions

Answer 285443 by mananth(12270) About Me  on 2011-02-03 08:21:20 (Show Source):
You can put this solution on YOUR website!
nickels-------x
quarters--------x-7
total $ 2.15 = 215 cents
...
5x+25(x-7)=215
5x+25x-175=215
30x=215+175
30x=390
/30
x=13=====> nickels
13-7 = 6 =====> quarters


Age_Word_Problems/403730: james is 4 years older than danny. 2 years ago, James was 5 years as old as danny. how old was james today?
1 solutions

Answer 285441 by mananth(12270) About Me  on 2011-02-03 08:17:34 (Show Source):
You can put this solution on YOUR website!
Danny ---------- x years
James ----------- x+4 years
..
2 years ago
Danny = x-2
James = (x+4)-2=======> x+2
...
x+2=5(x-2)
x+2=5x-10
5x-x=2+10
4x=12
/3
x=4 years===========> Danny's age
James============> 4+4 = 8 years


Graphs/403704: I need to graph the following equation on a plane and I am not sure how to do that.
2x+3y≤6

Thank you
1 solutions

Answer 285432 by mananth(12270) About Me  on 2011-02-03 00:38:02 (Show Source):
You can put this solution on YOUR website!
2x%2B3y%3C=6
3y%3C=-2x%2B6

x=0,y=2(0,2)
y=0,x=3(3,0)
..
The boundary
plot the points and draw the line

Since y is less than something all points below the line are solutions to the equation. The shaded area
graph%28300%2C300%2C-5%2C5%2C-5%2C5%2Cy%3C=%28-2x%2F3%29%2B2%29%29




Polynomials-and-rational-expressions/403614: The length of the side of a rectangular desk is given by 6x - 3y cm. The length of the front is given by 6x + 3y cm. What is an algebraic expression for the area of the top of the rectangular desk? Include correct units as part of your answer.

1 solutions

Answer 285360 by mananth(12270) About Me  on 2011-02-02 20:06:08 (Show Source):
You can put this solution on YOUR website!
The length of the side of a rectangular desk is given by 6x - 3y cm. The length of the front is given by 6x + 3y cm. What is an algebraic expression for the area of the top of the rectangular desk? Include correct units as part of your answer.

The length of the side of a rectangular desk is given by 6x - 3y cm.
The length of the front is given by 6x + 3y cm.
...
Area = L*W
Area = (6x-3y)(6x+3y)
Area = (36x^2-9y^2) cm^2


Travel_Word_Problems/403604: the length of a rectangular frame is 53cm.for what widths would the perimeter be greater than 160cm?

1 solutions

Answer 285359 by mananth(12270) About Me  on 2011-02-02 20:03:30 (Show Source):
You can put this solution on YOUR website!
the length of a rectangular frame is 53cm.for what widths would the perimeter be greater than 160cm?
let width be w
..
Perimeter = 2*(L+W)
Perimeter = 2(53+W)
..
2(53+W)>160
/2
53+W >80
-53
w>80-53
W>27 cm


Graphs/403600: Use substitution or elimination to solve each system of equations.
2x + 5y= 16
5x - 2y=11
1 solutions

Answer 285357 by mananth(12270) About Me  on 2011-02-02 19:59:03 (Show Source):
You can put this solution on YOUR website!
2x + 5y= 16..............1
5x - 2y=11...............2
...
multiply (1) by 2 & (2) by 5
we get
4x+10y=32
25x-10y=55
add them
29x=87
/29
x=3
...
plug value of x in (1)
2x+5y=16
2*3+5y=16
6+5y=16
5y=10
/5
y=2



Money_Word_Problems/403597: Gunther invested $10,000 in two mutual funds. One of the funds rose 6 percent in one year and the other rose 9 percent in one year. If Gunthers investment rose a total of $684 in one year, how much did he invest in each mutual fund?
Yes, this is my son's 7th graded algebra homework. He's learning to solve systems of equations so my first inclination is to .06x +.09y=684 and x + y = 10,000
1 solutions

Answer 285353 by mananth(12270) About Me  on 2011-02-02 19:53:20 (Show Source):
You can put this solution on YOUR website!
Yes, this is my son's 7th graded algebra homework. He's learning to solve systems of equations so my first inclination is to .06x +.09y=684 and x + y = 10,000
0.06x +0.09y=684 ...........1
x + y = 10,000 ............2
...
multiply (1) by 100
we get
6x+9y=68400................3
Multiply (2) by -6
we get
-6x-6y=-60000.............4
Add (3) & (4)
6x-6x+9y-6y=68,400-60,000
3y=8,400
/3
y=2800
So x= 7,200


Rectangles/403593: Suppose that the width of a certain rectangle is 5 inches less than its length. The area is numerically 16 less than twice the perimeter. Find the length and width of the rectangle.

1 solutions

Answer 285349 by mananth(12270) About Me  on 2011-02-02 19:45:55 (Show Source):
You can put this solution on YOUR website!
Suppose that the width of a certain rectangle is 5 inches less than its length. The area is numerically 16 less than twice the perimeter. Find the length and width of the rectangle.
...
length = L
width = L-5
..
Area = L(L-5)
...
Perimeter = 2(L+L-5)
Perimeter = 2(2L-5)
...
L(L-5)=2*2(2L-5)-16
L^2-5L=8L-20-16
L^2-5L-8L=-20-16
L^2-13L=-36
L^2-13L+36=0
L^2-9L-4L+36=0
L(L-9)-4(L-9)=0
(L-9)(L-4)=0
So L= 4 OR 9
The dimensions are 9 by 4 feet