Question

nancy found that $x = 1$ is one solution to the quadratic equation $(x + 2)^2 = a$. what is the value of $a$? $-3$ $3$ $9$ $-9$

Explanation:

Step1: Substitute $x=1$ into equation

Substitute $x=1$ into $(x+2)^2=a$:
$$(1+2)^2=a$$

Step2: Simplify left-hand side

Calculate the sum and square:
$$3^2=a$$
$$9=a$$

Answer:

9