Question

Factor 16x2+24x+9.

Answer 1

a=16
b=24
c=9
find two factors of a*c that add up to be b
a*c=(16)(9)=(8)(18)=(4)(36)=(12)(12)
12+12=24
so 16x2+12x+12x+9 can be factored by grouping

Answer 2

what do first two terms have in common
4x
so factor out 4x giving you
4x(4x+3)+12x+9
what do the second terms have in common
3
so factor out 3 giving you
4x(4x+3)+3(4x+3)
so 4x+3 is in both of the above terms
factor that out giving you
(4x+3)(4x+3)
(4x+3)^2