Consider this option:
1. if to re-write the condition, it is given: total time t=8 hours; upstream=downstream=6 miles; V_boat=4 m/h., V_current=V=?
2. note, that total time=time_upstream+time_downstream, where time_upstream=6miles/(V_boat-V) and time_downstream=6miles/(V_boat+V). Using this it is possible to make up and solve the following equation:

answer: √10
P.S. the roots of the equation are √10 and (-√10), only positive values is needed for V.
Y = 2x - 5
3x + 8y + 32 = 56
3x + 8(2x - 5) + 32 = 56
3x + 8(2x) - 8(5) + 32 = 56
3x + 16x - 40 + 32 = 56
19x - 8 = 56
<u> + 8 + 8</u>
<u>19x</u> = <u>64</u>
19 19
x = 3.4
y = 2(3.4) - 5
y = 6.8 - 5
y = 1.8
(x, y) = (3.4, 1.8)
Answer:
C
Step-by-step explanation:
Attachment
Hi there!

Our interval is from 0 to 3, with 6 intervals. Thus:
3 ÷ 6 = 0.5, which is our width for each rectangle.
Since n = 6 and we are doing a right-riemann sum, the points we will be plugging in are:
0.5, 1, 1.5, 2, 2.5, 3
Evaluate:
(0.5 · f(0.5)) + (0.5 · f(1)) + (0.5 · f(1.5)) + (0.5 · f(2)) + (0.5 · f(2.5)) + (0.5 · f(3)) =
Simplify:
0.5( -2.75 + (-3) + (-.75) + 4 + 11.25 + 21) = 14.875
Answer:
You should stick with option D