Ido all things in zero sums in my head is that possible to be a zero?

Which expression is equivalent to? assume x > 0 and y > 0.

Line l passes through points (0,4) and (3,6) what is the slope of a line that is parallel to line l -2/3 -3/2 2/3 3/2

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?