Chapter 5 - Exponents and Polynomials - 5.2 - Multiplying Monomials - Problem Set 5.2 - Page 200: 57

$28x^3y-7x^2y+35xy$

Using $a(b+c)=ab+ac$ (or the Distributive Property), the given expression, $ 7xy(4x^2-x+5) ,$ is equivalent to \begin{array}{l}\require{cancel} 7xy(4x^2)+7xy(-x)+7xy(5) \\\\= 28x^3y-7x^2y+35xy .\end{array}