Find all real values of $s$ such that $x^2 + sx + 144 - 44$ is the square of a binomial.
Simplify as
x^2 + sx + 100
To be a square of a binomial the discriminant must = 0
s^2 - 4(1)(100) = 0
s^2 = 400 take both roots
s = -20 , 20