Answer:
120
Step-by-step explanation:
Answer: XY - Z
The value of Z cannot be larger than XY.
For instance, if he went shopping with XY = 25 dollars and spent Z = 9 dollars, then he's left with XY-Z = 25-9 = 16 dollars.
Let x = liters 20% solution to be added
then
.12(12) + .20x = .14(12+x)
.12(12) + .20x = .14(12+x)
1.44 + .20x = 1.68 + .14x
.20x = .24 + .14x
.06x = .24
x = 4 liters
Hope this helped!!