Question

What is the result of substituting for y in the bottom equation y=x+3 y=x^2+2x-4

Answer 1

Question:

What is the result of substituting for y in the bottom equation? y = x – 3 y = x2 + 2x – 4 A. (x – 3) = x2 B. y = (x – 3)2 + 2(x – 3) – 4 C. x – 3 = x2 + 2x – 4 D. y = x2 + 2x – 4 – (x – 3)

Answer:

Option C: $x-3=x^{2}+2 x-4$ is the resulting equation

Explanation:

Given that $y=x+3$ and $y=x^{2}+2 x-4$

We need to determine the resulting equation by substituting the value of y in the equation $y=x^{2}+2 x-4$

Option A: $x-3=x^{2}$

Substituting the value of y in the second equation does not results the equation $x-3=x^{2}$ because the last two terms $2x-4$ is missing.

Hence, Option A is not the correct answer.

Option B: $y=(x-3)^{2}+2(x-3)-4$

This is not the resulting expression because instead of substituting the value for y, it has been wrongly substituted for x.

Hence, Option B is not the correct answer.

Option C: $x-3=x^{2}+2 x-4$

This is the resulting expression because substituting $y=x+3$ in the second equation, we get, $x-3=x^{2}+2 x-4$

Hence, Option C is the correct answer.

Option D: $y=x^{2}+2 x-4-(x-3)$

This is not the resulting expression because instead of substituting the values for y, the value of y has been subtracted.

Hence, Option D is not the correct answer.