Question

(x-5)(x+8)-(x+4)(x-1)=-36

(x-3)(x+7)-(x+5)(x-1)=-16

 обоснуйте тождество

Answer 1

$(x-5)(x+8)-(x+4)(x-1)=-36\x^2+8x-5x-40-x^2+x-4x+4=0x^2+0x-36=-36\ (x-3)(x+7)-(x+5)(x-1)=-16\x^2+7x-3x-21-x^2+x-5x+5=0x^2+0x-16=-16$

Answer 2

X^2+8x-5x-40-x^2+x-4x+4=-36

-36=-36

_____

x^2+7x-3x-21-x^2+x-5x+5=-16

-16=-16