Option A. зу + 12 is the right answer
Step-by-step explanation:
The substitution method consists of finding the value of a variable from one equation and then putting it into another equation to find the value of other variable.
Given equations are:

We have to isolate x in the 2nd equation

Multiplying equation by -1

Subtracting 3y from both sides

Hence,
Option A. зу + 12 is the right answer
Keywords: linear equations, Variables
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