Question

Giúp vs cần gấp 

Answer 1

c: Ta có: \(\left(x^2-1\right)\left(x+2\right)-\left(x^2+5\right)\left(x+1\right)\)

\(=x^3+2x^2-x-2-x^3-x^2-5x-5\)

\(=x^2-6x-7\)