1st photo is simplifying the entire account.
2nd photo is how i simplified the x^2 + 9x + 18 equation into (x+3).(x+6) .
3rd photo is the remaining part of the 2nd photo.
Answer: 2nd option = (x+6)(x+5)
8 cubic cm equal to 8 milliliters. It does not equal 2.5 mm.