C would be the lowest cost at 91 cents per juice box
First ask yourselfhat needs to be dristributed.
That would be -1 (x-9)
To distribute you have to multiply the number out side of the parentheses (-1) by each term inside the parentheses( x and -9)
-1×x=-x
-1×-9=9
Now the expression is
-x+9+4x
To simplify you have to combine like terms (4x and-x)
4x-x=3x
Your answer is 9+3x or 3(3+x).
2(4+5x) is the right answer
