Question

what is the first step in solving the quadratic equation $x^2 - 40 = 0$?
taking the square root of both sides of the equation
adding 40 to both sides of the equation
squaring both sides of the equation
subtracting 40 from both sides of the equation

Explanation:

To solve the quadratic equation \( x^2 - 40 = 0 \), we aim to isolate \( x^2 \) first. The equation has \( x^2 - 40 \) on the left. To isolate \( x^2 \), we need to get rid of the \(-40\). The inverse operation of subtraction is addition, so we add 40 to both sides. This gives \( x^2 = 40 \), which is the necessary step before taking the square root. Taking the square root would be the next step, squaring both sides is not needed here, and subtracting 40 would not isolate \( x^2 \).

Answer:

B. adding 40 to both sides of the equation