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