please help asap!!!

Question

In his? motorboat, Bill Ruhberg travels upstream at top speed to his favorite fishing? spot, a distance of
112
112 ?mi, in
4
4 hr.? Returning, he finds that the trip? downstream, still at top? speed, takes only
3.5
3.5 hr. Find the rate of? Bill's boat and the speed of the current. Let x? = the rate of the boat in still water and y? = the rate of the current.

Answer 1

 

Yes, let x = rate of boat in still water

  and let y = rate of the current

 

So upstream:    4 * (x - y) = 112    [ you can include the units to see that this is the correct formulation for the

                                                      upstream trip:   4 hrs * (x - y) mi/hr = 112 mi,  as the 'hrs' cancel ]

 

The downstream trip gives you a 2nd equation (hint: you add x and y), and then those two equations can be solved for x & y.