x^2+5x+6
Is in the form:
ax^2+bx+c
So:
a=1
b=5
c=6
First, find the product of a and c
a x c = 1 x 6 = 6
List products that equal (a.c)
6 x 1 = 6
2x3 = 6
find the expression that when added is equal to b (5)
2+3 =5
Rewrite the trinomial with the new numbers in the middle term:
x^2+2x+3x+6
Isolate similar terms and factor out the greatest common factor
(x^2+3x) + (2x+6)
x (x+3) + 2 (x+3)
Factor out (x+3) and rewrite
(x+2) (x+3)
Answer D (x+2)