Question

Which of the following equations shows how substitution can be used to solve

the following system of equations?

Answer 1

Answer: Choice B)

2x+5(2x+3) = 3

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Reasoning:

We start with the second equation 2x+5y = 3

Since y = 2x+3 from the first equation, we can replace every copy of y with (2x+3). This replacement is valid because y and 2x+3 are the same.

So that's how we go from 2x+5y = 3 to 2x+5(2x+3) = 3

This replacement is done to get rid of the y variable, and it allows us to solve for x later on.