annkorby1402

Ответ

620.

1) (a2-1)(a2+1) = a4-1

2) 5a/2+a2/2-25-5a/2+25 = a2/2

621

1) a2+6a+9+ a2-6a+9 = 2a2+18

2) 16a2+8ab+b2-16a2+8ab-b2 = 16ab

622

1) 1+a+a2-a-a2-a3+a3 = 1

2) 1/8+c2/4+c4/2-c2/4-c4/2-c6+c6 = 1/8