# Math Help - Solve by substitution - Help

1. ## Solve by substitution - Help

I have to solve this by way of the substitution method, please help.

1/5x + 2/3y = -73/5

3x-y=12

One more:

5x+7y=15

x=6-2y

2. Originally Posted by highdrake
I have to solve this by way of the substitution method, please help.

1/5x + 2/3y = -73/5

(1/5)x + (2/3)(3x-12) = -73/5

3x-y=12, solve for y ... y = 3x-12 ... substitute for y in the above equation, then solve for x

One more:

5x+7y=15

5(6-2y) + 7y = 15

x=6-2y same drill with x, then solve for y
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