(x-3)(x+4) равно x(x+1)-12

Question

(x-3)(x+4) равно x(x+1)-12

Answer 1

X^2+x-12=x^2+x-12
x^2+x-12-x^2-x+12=0
0=0

Answer 2

X^2+4x-3x-12=x^2+x-12
x^2+x-12+12-x-x^2=0