Question 59460
Use the substitution methods to solve for y and then subtiture the result in the original equation.
Step1. Solve for y
x+3y=-9
x+3y-x=-9-x
3y/3=-x/3-9/3
y=-1/3x-3
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Step2.===>now subtitute (-1/3x-3) for y in x + 3y = -9
x +3(-1/3x-3) =-9
x -3(x+9/3) =-9
x - x-9 = -9
-9 = -9
x= any real numbers (infinite number of solution)

Pvaka