no one can do that. it doesn't make scence
x^2-19x+90 (x-9) (x-10)
x(x - 19)(x - 1)
(3x + 1)(x + 6)
x3 + 2x2 - 19x - 20 = x3 + x2 + x2 + x - 20x - 20 = x2(x + 1) - x(x + 1) - 20(x + 1) = (x + 1)(x2 + x - 20) = (x + 1)(x - 4)(x + 5)
(x+7)(x+12)
Divide by x: x(x2 - 20x + 19); = x(x -1)(x - 19)
x=-2
(x - 10)(x - 9)
x2 - 19x + 60 = x2 - 15x - 4x + 60 = x(x - 15) - 4(x - 15) = (x - 15)(x - 4)
Factor as : (x+9)(x+10) using the first terms ( x terms) multiply to x2; the last terms multiply to 90; the sum of 9x + 10 x = 19x
(x + 12)(x + 7)