So with #7 you are going to divide 24 feet by 2 feet which will give you an answer of 12 feet.
And for #6 you are going to want to put the equation set up as 15+4x=12+6x
X = 11 because if you take 11 x 2 then you get 22 then add 5 to it then you got 27 or if you do it the algebraic way subtract 5 from 27 to get 2x = 22 then divide both sides by 2 to get x = 11