Answer:
The first one
Step-by-step explanation:
Make 3x+6 into 3(x+2)
Separate x²+5x+6 into (x+2)(x+3)
Cross out both x+3
6x÷3
Put x+2 together to make (x+2)²
[tex]\frac{2x}{(x+2)^2}[/tex]