jenny has an 18in sub she cuts it so demi gets half of what

jenny has an 18in sub she cuts it so demi gets half of what she gets and drew gets 3/4 of what jenny gets. what is the length of each persons sandwich this is as far as I get then I get stuck.

let x = jennys
x+x/2+3/4x=18

Where do I go from here

Solution

x+x/2+(3/4)x=18

Let\'s multiply everything by 4. We are selecting 4 because this number is easily divisible by either 2 or 4...
4(x+x/2+(3/4)x)=18(4)
4x+(4x)/2+(4)(3/4)x=18(4)
4x+2x+3x=72
9x=72
x=8 inches=Jenny\'s share
x/2=4 inches=Demi\'s share
(3/4)x=6 inches=Drew\'s share

8 + 4 + 6=18