## College Algebra 7th Edition

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) $1020^{2}-1010^{2}=(1020-1010)(1020+1010)=10(2030)=20300$