Alvin wants to know what his average paddling rate was for a canoe trip to a campsite. on the way there it took him 7 hours against a river current of 4 km/ hr. on the way back, the same distance took him 5 hours with the same 4 km/hr current. let r = alvin's average paddling rate.

7 * (r - 4) = 5 * (r + 4) --> r = 24 km/h

Alvin's average paddling rate = 24 km/hr

Step-by-step explanation:

Let r = Alvin's average paddling rate and s = distance of canoe trip.

On the way he is paddling against a river current of 4 km/ hr, so resultant rate of paddling is given by

                r' = r - 4

Time taken for on the way = 7 hours

So to cover s distance he takes 7 hours at a rate of r - 4.

                   s = 7 ( r - 4)

                   s = 7r - 28 eqn 1

On the way back he is paddling in the direction of a river current of 4 km/ hr, so resultant rate of paddling is given by

                r' = r + 4        

Time taken for on the way back = 5 hours

So to cover s distance he takes 5 hours at a rate of r + 4.

                   s = 5 ( r + 4)  

                   s = 5r + 20 eqn 2    

eqn 1 - eqn 2 gives

                    s -s = 7r - 28 - ( 5r + 20)

                       0 = 2r - 48

                        r =  24 km/hr        

Alvin's average paddling rate = 24 km/hr

(1, –1), (16, –4), (36, –6)

step-by-step explanation:

given that the function is

this can also be written as

we have to graph this function and check which list of points lie on the graph

see attachment for graph:

we find that the points lying are (1,-1) (16,-4) and (36,-6)

since square root is there we find that x can only be posiitve but y can be since square root both positive and negative.