Question

Упростите выражение:
(а-10)^2-(а-5)(а+5)

Answer 1

(a-10)^2-(a-5)(a+5)=

(a-10)(a-10)-(a-5)(a+5)=

(a^2-10a-10a+100)-(a^2+5a-5a-25)=

a^2-10a+100-a^2-5a+5a+25=

a^2-a^2-10a-10a-5a+5a+25=

-20a+125