## Algebra: A Combined Approach (4th Edition)

(a) $(x+2y)(x+7y)$ (b) $(a-3b)(a-10b)$
Part (a): $x^{2}+9xy+14y^{2}=$ $x^{2}+2xy+7xy+14y^{2}=$ $x(x+2y)+7y(x+2y)=$ $(x+2y)(x+7y)$ Part (b): $a^{2}-13ab+30b^{2}=$ $a^{2}-3ab-10ab+30b^{2}=$ $a(a-3b)-10b(a-3b)=$ $(a-3b)(a-10b)$