Chapter 5 - Section 5.3 - Special Products - Exercise Set - Page 368: 71

$70y^2+2y-12$

Using $(a+b)(c+d)=ab+ad+bc+bd$ or the FOIL Method, the product of the given expression, $ (7y+3)(10y-4) ,$ is \begin{array}{l}\require{cancel} 7y(10y)+7y(-4)+3(10y)+3(-4) \\\\= 70y^2-28y+30y-12 \\\\= 70y^2+2y-12 .\end{array}