Answer
$(x-9)(x-10)$
Work Step by Step
The first term in each binomial must be x, since $x^2$ has no coefficient.
The operation in each binomial must be subtraction, since the trinomial has a positive and a negative term.
$-9+(-10)=-19$ and $-9\times(-10)=90$, so the other two terms are -9 and -10.
