SOLUTION: i know how to do algebra problems using the addition method, however i can not get the answer to one question the problem is 1/4x -1/6y=-1 -1/18x +

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Question 651677: i know how to do algebra problems using the addition method, however i can not get the answer to one question
the problem is 1/4x -1/6y=-1

-1/18x +1/15y=2


x= 36 y= ? i can not even find x. someone gave me the answercan you show me how to work this out. thank you
Found 2 solutions by Edwin McCravy, MathTherapy:
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
system%28+%0D%0A%0D%0Ax+-%281%2F6%29y=-1%2C%0D%0A%0D%0A%28-1%2F18%29x%2B%281%2F15%29y=2+%29

First remove the fractions by multiplying the first equation through
by 6 and the second equation though by 90

system%28+%0D%0A%0D%0A6x+-y=-6%2C%0D%0A%0D%0A-5x%2B6y=180+%29

Next multiply the first equation through by 6

system%28+%0D%0A%0D%0A36x+-6y=-36%2C%0D%0A%0D%0A-5x%2B6y=180+%29

Now add corresponding terms and the y-terms cancel

31x = 144
  x = 144%2F3

Since that is a bad fraction, and hard to substitute,
go back to

system%28+%0D%0A%0D%0A6x+-y=-6%2C%0D%0A%0D%0A-5x%2B6y=180+%29

and eliminate x by multiplying the first equation by 5
and the second equation through by 6

system%28+%0D%0A%0D%0A30x+-5y=-30%2C%0D%0A%0D%0A-30x%2B36y=1080+%29

Now add corresponding terms and the y-terms cancel

31y = 1050
  y = 1050%2F31

Edwin

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

i know how to do algebra problems using the addition method, however i can not get the answer to one question
the problem is 1/4x -1/6y=-1

-1/18x +1/15y=2


x= 36 y= ? i can not even find x. someone gave me the answercan you show me how to work this out. thank you

%281%2F4%29x+-+%281%2F6%29y+=+-+1
3x – 2y = - 12 ----- Multiplying by LCD, 12 ----- eq (i)

-+%281%2F18%29x+%2B+%281%2F15%29y+=+2+
- 5x + 6y = 180 ------ Multiplying by LCD, 90 ------- eq (ii)
9x – 6y = - 36 ------ Multiplying eq (i) by 3 ---- eq (iii)
4x = 144 ------ Adding eqs (iii) & (ii)

x = 144%2F4, or highlight_green%2836%29

3(36) – 2y = - 12 ------ Substituting 36 for x in eq (i)
108 – 2y = - 12
– 2y = - 12 – 108
– 2y = - 120

y = %28-+120%29%2F-+2, or highlight_green%2860%29

You can do the check!!

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