Question

Which product of prime polynomials is equivalent to 8x4 + 36x3 – 72x2?

4x(2x – 3)(x2 + 6)
4x2(2x – 3)(x + 6)
2x(2x – 3)(2x2 + 6)
2x(2x + 3)(x2 – 6)

Answer 1

Answer: (b) 4x2(2x – 3)(x + 6)

Explanation:

Answer 2

`8x^(4)+36 x^(3)-72 x^(2)` , taking
`4x^(2)` as the common factor


`4x^(2)(2 x^(2) +9x-18)` , factorising the expression in bracket


`4x^(2)[2 x^(2) +12x-3x-18]`

`4 x^(2) [(2x(x+6)-3(x+6)]`

`4 x^(2) (2x-3)(x+6)`

Correct answer is the second expression