Question

What is the solution of the system y= -3x and 3x+2y=6

Answer 1

Since you already have y (somewhat) substitute the y in 2y with -3x to get:
3x+2(-3x)=6.
Simplify (multiplication and then adding like things):
3x-6x=6
-3x=6
x=-2

Then to find what y really is, substitute -2 (the answer for x) into the equation:
y=-3(-2)
Multiply the two numbers to get y=6.

Answer 2

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