So I'm guessing that the x2 is your way of saying 2 is the exponent right? In that case the equation would be 8x^2 + 12x Well you would have to pull out the gcf which in this case will be 4x after pulling out the gcf you should get 4x(2x + 3)
So if 18 plus 1/4 of the number is the number the means 18 is 3/4 of the number so 18 divided by 3 is 6 so 1/4 = 6 now add 6 to 18 to get 4/4 of the number which is 24 number = 24