## College Algebra (11th Edition)

(a) and (b) follow the pattern for $(a + b)^{2}$ = $a^{2}$ + 2ab + $b^{2}$. (c) and (d) follow the pattern for (a + b)(a - b) = $a^{2}$ - $b^{2}$ We can then check the factorizations with FOIL.