SOLUTION: the original problem was 3x/8-3y/5=33/80 4x/7+4y/5=37/35 i multiplied the first equation by 80 to get 30x-48y=33 then i multiplied the second by 35 to get 20x-28y=37 i

Question 666131: the original problem was
3x/8-3y/5=33/80
4x/7+4y/5=37/35
i multiplied the first equation by 80 to get 30x-48y=33
then i multiplied the second by 35 to get 20x-28y=37
i multiplied the top equation by 2 to get 60x-96y=66
then multiplied the second quation by -3 to get -60x+84y=-111
the 60x and -60x cancel so i have -96y=66 and 84y=-111
this is where i got confused, because i got 180y=-45... and then y=-1/4... what steps did i miss?

Answer by swincher4391(1107) (Show Source): You can put this solution on YOUR website!
Let's go through your steps:
Multiply (1) by 80. Good.
30x - 48y = 33
Multiply (2) by 35. Also good.
20x + 28y = 37
Multiplying (1) by 2 and multiplying (2) by 3 will allow us to use elimination:
60x - 96y = 66
60x + 84y = 111
-180y = -45
y = 1/4
30x - 48(1/4) = 33
30x - 12 = 33
30x = 45
x =45/30 = 3/2
(3/2, 1/4)

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