Ireally need on these equations the last pic and this one im in danger of failing

D = rt, distance = rate * time

so, we know the boat is going at a rate of "x", and the current has a rate of "y".

ok... from A to B, the boat is going downstream, the speed of the boat is not really "x", is " x + y ", because, is going with the stream and thus the current is adding "y" to its speed.

now, from B to A, the boat is going upstream, against the current, is not really going "x" fast either, is going " x - y ", because the current is eroding/subtracting from it's speed.

ok... since, since the towns A and B didn't really move, unless they're floating towns, but they're not, so, the distance from A  to B is the same distance from B to A, say they're at a distance "d".