Solving by elimination... yikes!!

x + 2y = 12
-x + 7y = 6

this is tricky as I am used to using substitution. please fellow answerers...help me!!!

add the equations and the x's drop out and we get

9y = 18
y = 2

put 2 in for y in one of the original equations and solve for x. let's choose equation 1 and we get

x + 2(2) = 12
x + 4 = 12
x = 8

(8,2)

Think about it as combining the two equations.
You want to cancel one variable
The way it setup is easy because you already have -x and x
So:

x + 2y = 12
-x + 7y = 6. Add then: the x cancel and you get

9y = 18
y = 2
And plug in to either equation and solve for x

x + 2y = 12
-x + 7y = 6
------------------
9y = 18 {added the two equations together}
y = 2 {divided both sides by 9}

x + 2y = 12 {the top equation}
x + 2(2) = 12 {substituted 2, in for y, into the top equation}
x + 4 = 12 {multiplied 2 by 2}
x = 8 {subtracted 4 from both sides}

x = 8 and y = 2

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