Question

2(c-1)(c+2)-(c+6)^2

Answer 1

(2c-2)(c+2)-(c^2+12c+36)=2c^2+4c-2c-4-c^2-12c-36=c^2-10c-40

Answer 2

2(с-1)(с+2)-(с+6)^2=(2с-1)(с+2)-(с^2+12c+36)=2c^2-2c+4c-4-c^2-12c-36=c^2-10c-40.

Answer 3

спасибо !