Answer: Substitution
Step-by-step explanation:
GIVEN:
y=3x
2x+4y=12
Then, 2x+4(3x)=12
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Substitution: replacing one variable in terms of another variable.
As we can see from the given aspects, y=3x, and the conclusion expression has no y instead of 3x. This means it represented y in terms of x, which fits the definition of substitution that replaces one variable.
Hope this helps!! :)
