Question

How do you factor - 8x2 + 28x +60​

Answer 1

Answer:

4 • (x - 5) • (2x + 3)

Step-by-step explanation:

Step-1 : Multiply the coefficient of the first term by the constant   2 • -15 = -30  

Step-2 : Find two factors of  -30  whose sum equals the coefficient of the middle term, which is   -7 .

     -30    +    1    =    -29  

     -15    +    2    =    -13  

     -10    +    3    =    -7    That's it  

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -10  and  3  

                    2x2 - 10x + 3x - 15

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

                   2x • (x-5)

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

                   3 • (x-5)

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

                   (2x+3)  •  (x-5)

            Which is the desired factorization