Just by looking at this question, I dont know what im supposed to solve. Im guessing we are just trying to find how many days until Mika runs out of money.
Mika has $12 and spends $2 each day.
If we turn this into an equation, we will get 12-2x=0
12-2x=0 subtract 12 from both sides
-2x=-12 multiply both sides by -1
2x=12 divide by 2
x=6
Mika will run out of money in 6 days