Question

Factor completely. 9x4 + 12x3 – 45x2 – 60x

A. 3x(x2 – 5)(3x – 4)

B. 3x(x2 – 6)(3x + 10)

C. 3x(x2 – 5)(3x + 4)

D. 3x(x2 + 5)(3x – 4)

Answer 1

the answer is C if not sorry

Answer 2

Answer: The correct option is

(C)
`3x(x^2-5)(3x+4).`

Step-by-step explanation: We are given to completely factor the following bi quadratic expression :

`E=9x^4+12x^3-45x^2-60x~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)`

Since the given expression does not contain the constant term, so we will take out the x-term common and then will try to factorize the remaining cubic expression.

The factorization of expression (i) is as follows :

`E\\\\=9x^4+12x^3-45x^2-60x\\\\=3x(3x^3+4x^2-15x-20)\\\\=3x(x^2(3x+4)-5(3x+4))\\\\=3x(x^2-5)(3x+4).`

Thus, the required factored form of the given expression is
`3x(x^2-5)(3x+4).`

Option (C) is CORRECT.