SOLUTION: Please help. Solve the system by substitution. 4x+2y=8 y=-3x+7 Thanks JMS

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Question 116202: Please help.
Solve the system by substitution.
4x+2y=8
y=-3x+7
Thanks
JMS
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system
4x%2B2y=8
y=-3x%2B7



4x%2B2%28-3x%2B7%29=8 Plug in y=-3x%2B7 into the first equation. In other words, replace each y with -3x%2B7. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


4x%2B-6x%2B14=8 Distribute


-2x%2B14=8 Combine like terms on the left side


-2x=8-14Subtract 14 from both sides


-2x=-6 Combine like terms on the right side


x=%28-6%29%2F%28-2%29 Divide both sides by -2 to isolate x



x=3 Divide




Now that we know that x=3, we can plug this into y=-3x%2B7 to find y



y=-3%283%29%2B7 Substitute 3 for each x


y=-2 Simplify


So our answer is x=3 and y=-2