Answer:
4 [miles].
Step-by-step explanation:
1) the condition 'the entire trip took 5 hours' can be written as (where t_us - time spent upstream, t_ds - time spent downstream)

2) but the distance [D] upstream is equal the distance downstream, then the condition above can be written:

3) finally,

D=5*4/5=4 [miles].
Ok so
-10, -6
4,-6
-3,-13
-3,1
should be it
2 equations: the first one is the sum of 2 unknown numbers x and y: x + y = 72. Now the difference is 25, so x - y = 25. Solve the first equation for y: y = 72 - x. Sub that into the second equation to solve for x: x - (72 - x) = 25. x - 72 + x = 25 and 2x - 72 = 25. Therefore, 2x = 97 and x = 48.5 That's the larger of the 2 numbers; since we subtracted y from x we defined x as the larger of the 2. Just for fun, plug x in to find that y = 23.5
M = y2-y1/x2-x1
m = 7- (-2)/ -6-(-7)
m = 9/1
slope = 9