+1501 Find all real values of $s$ such that $x^2 + sx + 144 - 44$ is the square of a binomial.
+1950 First off, let's combine like terms to get x2+sx+100.
For this to be a square of a binomial, we must recognize that s is equal to double the square root of 100.
Solving this we get s=20.
Indeed, x2+20x+100=(x+10)2.
However, we also get s=-20.
We have x2−20x+100=(x−10)2.
This means s=-20, 20
Thanks! :)
(Haha, this is the post that got me to 200 points!)
