SOLUTION: Solve each system by substitution 7x-4y=9 -3x+5y=-17

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Solve each system by substitution 7x-4y=9 -3x+5y=-17      Log On


   

Question 755791: Solve each system by substitution
7x-4y=9
-3x+5y=-17
Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
from 7x-4y=9 we get
%0D%0Ax=%284y%2B9%29%2F7%0D%0A
%0D%0A-3%284y%2B9%29%2F7%2B5y=-17%0D%0A

m7:
%0D%0A-3%284y%2B9%29%2B35y=-119%0D%0A

y=(-119+27)/(35-12)=-4

so that means

%0D%0Ax=%284y%2B9%29%2F7=%284%28-4%29%2B9%29%2F7=-1%0D%0A

:)