SOLUTION: solve the system of equations: x+5y= -7 -2x-3y=7

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Question 187471: solve the system of equations:
x+5y= -7
-2x-3y=7
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


Givensystem%28x%2B5y=-7%28EQN1%29%2C-2x-3y=7%28EQN2%29%29
In EQN 1 we get----> 5y=-7-x---->cross%285%29y%2Fcross%285%29=%28-7-x%29%2F5
y=%28-1%2F5%29x-7%2F5, EQN 3, which we substitute in EQN 2:
-2x-3%28highlight%28%28-1%2F5%29x-7%2F5%29%29=7
-2x%2B%283%2F5%29x%2B21%2F5=7--->%28-10x%2B3x%29%2F5=7-21%2F5--->-7x%2F5=%2835-21%29%2F5
-7x%2F5=14%2F5--->-7x%2Fcross%285%29=14%2Fcross%285%29
cross%28-7%29x%2Fcross%28-7%29=14%2F-7}---->red%28x=-2%29, subst. in EQN3:
y=%28-1%2F5%29%28highlight%28-2%29%29-7%2F5=2%2F5-7%2F5=-5%2F5
red%28y=-5%2F5=-1%29
There you go, Point of Intersection (x,y)=(-2,-1)
We'll see the graph:
----->RED Line(EQN1); GREEN Line(EQN2)
Thank you,
Jojo