Question

Упростите выражение
(x+1)(x-1)-(x+5)(x-5)+(x+1)(x-5)

Answer 1

(x+1)(x-1)-(x+5)(x-5)+(x+1)(x-5)=x^2-1-x^2+25+x^2+x-5x-5=x^2-4x+19