The answer will be option a) 2y - x.
Let us take the number as y.
Twice the number will be 2y
Now if we subtract x from it, then the algebraic expression stands like this :
2y - x.
So answer will be option a.
Have the unknown amount = x
so 3x : 9x
you know how many kids meals were bought is equal to the ratio (3x = 12, so x=4)
you already know how many X's for the adults (9) so just multiply (9x4= 36)
lastly add since you need to find the total meals bought (36+12= 48)
Each friend should get 1/3 if there is only 2/3 left
