Chapter 4 - Polynomials - 4.6 Special Products - 4.6 Exercise Set - Page 277: 42

$-2m^2+19m-45$

Using $(a+b)(c+d)=ac+ad+bc+bd$ or the product of $2$ binomials, the given expression, $ (-m+5)(2m-9) $, is equivalent to \begin{array}{l}\require{cancel} -m(2m)-m(-9)+5(2m)+5(-9) \\\\= -2m^2+9m+10m-45 \\\\= -2m^2+19m-45 .\end{array}