Miguel has $20. He spends $6.25 on a movie ticket, $3.70 for snacks, and $1.25 for bus fare each way.

So we know Miguel has 20$ so from there we subtract the prices of the movies ticket, snacks, and the bus fares.

20 - 6.25 = 13.75

13.75 - 3.70 = 10.05

Since the bus fare is each way (to and back) we multiply 1.25 x 2

1.25 x 2 = 1.50

10.05 - 1.50 = 8.55

He has $8.55 left