Question 195589
Use substitution to solve each system of equations. 
1.y=x
x+=6 
That makes no sense.
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2.x+y=0
y=3 
--> x+3 = 0
x = -3
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3.y=-3x
x+y=8
x+(-3x) = 8
x-3x = 8
-2x = 8
x = -4