(x +8)(x -5) -(x -7)(x +7) =3
(х+8)(х-5)-(х-7)(х+7) = 3 х²-5х+8х-40-х²+49 = 3 х²-х²-5х+8х = 3+40-49 3х = -6 х = -6 : 3 х = -2 Ответ: -2.
X^2-5x+8x-40-x^2+7x-7x-49=3 3x=92