B. x=-8, y=-17.
First equate the two equations:
3x+7 = x-9
then simplify
2x = -16
x = -8
so y = x-9 = -8-9 = -17
Let y be a number
Note:
The product of 7 and a number is translated into 7y.
The sum of 10 and 7y is translated into 10 + 7y.
So the answer is B.
Since the ratio is 1:3, let's just say there are 4 parts to the punch
first, divide the 32cups by 4 parts: 32÷4=8
this means there are 8cups per part
the ratio 1:3 means orange got 1 part and water got 3 parts so 1 part×8cups=8cups
So, James punch required a total of 8 cups of orange concentrate.
