Answer
(a) 1055
(b) 484
(c) 20300
Work Step by Step
We use the formula $a^2-b^2=(a+b)(a-b)$:
(a) $528^{2}-527^{2}=(528-527)(528+527)=1(1055)=1055$
(b) $122^{2}-120^{2}=(122-120)(122+120)=2(242)=484$
(c) $1020^{2}-1010^{2}=(1020-1010)(1020+1010)=10(2030)=20300$
