Too bad that's not x^2 - 16x + 64 which factors to (x - 8)(x - 8)
Chat with our AI personalities
It is: 4x(1+4)
To factorise x3 + 5x2 - 16x - 80 I note that -80 = 5 x -16 and 5 & -16 are the coefficients of x2 and x. Thus I have: x3 + 5x2 - 16x - 80 = (x + 5)(x2 - 16) and the second term is a difference of 2 squares, meaning I have: x3 + 5x2 - 16x - 80 = (x + 5)(x + 4)(x - 4)
4(x + 2)(x + 2)
x + 4
x3 + 4x2 - 16x - 64 = (x + 4)(x + 4)(x - 4).