( x - 4)^2(x + 10) - 15(x -4) = 0
( x - 4)( (x-4)(x+10) - 15) =0
( x - 4)(x^2 + 6x - 40 - 15) = 0
( x - 4)(x^2 + 6x - 55) = 0
x - 4 = 0
x = 4
x^2 + 6x - 55 =0
D = b^2 - 4ac = 36 + 220 = 256 =16^2
x1 = ( - 6 + 16) / 2 = 5
x2 = ( - 6 - 16) / 2 = - 11
Ответ: уравнение имеет три корня: x1 = 5, x2 = - 11, x3 = 4.