Question #N795

If $x^2 + 2x - 3 = 0$, what is the value of $x^2 + 2x + 1$?
A. 1
B. 4
C. 7
D. 10

Correct Answer is: B

Notice that $x^2 + 2x + 1$ is a perfect square trinomial: $(x+1)^2$. Since we know $x^2 + 2x - 3 = 0$, we can add 4 to both sides of this equation to get $x^2 + 2x + 1 = 4$. Therefore, $x^2 + 2x + 1$ is equal to 4.