Question

(7a-8b)(a-2b)+(a-8b)(a-2b)

Answer 1

=[6a+(a-8b)](a-2b)+(a-8b)(a-2b)

=6a(a-2b)+(a-8b)(a-2b)+(a-8b)(a-2b)

=6a(a-2b)+2(a-8b)(a-2b)

=[6a+2(a-8b)](a-2b)

=(6a+2a-16b)(a-2b)

=(8a-16b)(a-2b)

=8乘以(a-2b)的平方

=8（a平方-4ab+4b的平方）

=8a平方-32ab+32b的平方