Question

(x-3)(x+7)-(x+8)(x-4)=11 докажите тождество

Answer 1

$x^{2} +7x-3x-21- x^{2} +4x-8x+32=11$
11=11

Answer 2

(x-3)(x+7)-(x+8)(x-4)=x^2+7*x-3*x-21-x^2+4*x-8x+32=(-21)+32=11