Question

What is the factored form of 4x2 + 23x – 72?

Answer 1

(x + 8 )(4x - 9)

using the a-c method

consider the factors of the product 4 × - 72 = - 288 which sum to + 23

The factors are + 32 and - 9

split the middle term using these factors

4x² + 32x - 9x - 72 ( factor by grouping )

= 4x( x + 8) - 9( x + 8)

take out the common factor ( x + 8)

= (x + 8 )(4x - 9 )

Answer 2

Assuming that the first number is four x squared, the answer is: (x+8)(4x-9)