Question

Упростите:
(2a-$2sqrt{7ab}$+7b)(2a+$2sqrt{7ab}$+7b)

Answer 1

(2a-2√(7ab)+7b)(2a+2√(7ab)+7b)=
=4a²+4a√(7ab)+14ab-4a√(7ab)-28ab-14b√(7ab)+14ab+14b√(7ab)+49b²=
=4a²+49b²