Answer:
Step-by-step explanation:
To solve means to find the x values of the equation:
-16x²+56x +72 =0; factor -8
-8*( 2x² -7x +9) =0
if we multiply two numbers and the answer is 0 then at least one of the numbers is 0. -8 is not 0 so 2x² -7x +9 must be 0. So you can further ignore the -8 in order to find the x.
2x² -7x +9 = 0 ; rewrite -7x as 2x-9x so you can factor
2x² +2x -9x +9 = 0
2x(x+1) -9(x+1) = 0 ; factor (x+1)
(x+1)(2x-9) = 0
Now again we have the product of two numbers is = 0
x+1 =0 ; x= -1
2x-9 =0 ; 2x=9 so x= 9/2
