Is it inside, on, or outside

If i have 20$ and i gave 5$ away how much i got

The square root of 9x plus 7 plus the square rot of 2x equall to 7

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?