Answer
$25$
Work Step by Step
With an expression that has the form $x^2 + bx$, add $(\frac{b}{2})^2$ to complete the square:
In the expression $x^2 + 10x$, $b$ is $10$; therefore, $(\frac{b}{2})^2$ is:
$(\frac{10}{2})^2$
Simplify the fraction:
$(5)^2$
Evaluate the exponent:
$25$
