Answer
$(d-5)(d-2)$
Work Step by Step
The 2 numbers whose product is $ac=
1(10)=10
$ and whose sum is $b=
-7
$ are $\left\{
-5,-2
\right\}.$ Using these two numbers to decompose the middle term of the given trinomial, $
d^2-7d+10
,$ then the factored form is
\begin{array}{l}
d^2-5d-2d+10
\\\\=
(d^2-5d)-(2d-10)
\\\\=
d(d-5)-2(d-5)
\\\\=
(d-5)(d-2)
.\end{array}