Factor 4x^2-9x-9 and show work.

please explain the steps taken

22x2 -  9x) -  9

Trying to factor by splitting the middle term

   Factoring  4x2-9x-9  

The first term is,  4x2  its coefficient is  4 .

The middle term is,  -9x  its coefficient is  -9 .

The last term, "the constant", is  -9  

Step-1 : Multiply the coefficient of the first term by the constant   4 • -9 = -36  

Step-2 : Find two factors of  -36  whose sum equals the coefficient of the middle term, which is   -9 .

     -36    +   1  =  -35  

     -18    +   2  =  -16  

     -12    +   3  =  -9  

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -12  and  3  

                    4x2 - 12x + 3x - 9

Step-4 : Add up the first 2 terms, pulling out like factors :

                   4x • (x-3)

             Add up the last 2 terms, pulling out common factors :

                   3 • (x-3)

Step-5 : Add up the four terms of step 4 :

                   (4x+3)  •  (x-3)

                                 Hope this helps!

Step-by-step explanation:

the sum of the interior angles should be 720 degrees. Thus, angle B is 108 degrees