Factorization: 3x ^ 2-36x + 60 =?

Factorization: 3x ^ 2-36x + 60 =?

=3(X^2-12X+20) 1 -10
=3(X-10)(X-2) 1 -2

If f (x) = 3x ^ 3-2x ^ 2 + kx-4 divided by X + 1, find K

If f (x) = 3x & sup3; - 2x & sup2; + kx-4 can be divided by X + 1, then K
From the meaning of the question, x + 1 is a factor of F (x), then x + 1 = 0, that is, x = - 1 must be a root of the equation f (x) = 0
f(-1)=3*(-1)³-2*(-1)²+k*(-1)-4=0
That is: - 3-2-k-4 = 0
k=-9.

Calculation: (8xn + 1-3xn-1) - 2 (- x + 9xn + 1-4xn)

The original formula = 8xn + 1-3xn-1 + 2x-18xn + 1 + 8xn. = - 10xn + 1 + 5xn + 2x-1