Answer:
2x+4 or 2(x+2)
Explanation:
I'm not very confident that I can give you a clear explanation while typing, but you can factor the equation which is one way how to do this.
2x^2 + 10x+12 = 2(x^2+5x+6)
= 2(x(x+3) + 2(x+3))
= 2(x+3)(x+2)
With that answer, you divide it by x+3 and get 2(x+2) or 2x+4