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.
Answer:
Somewhere around 27k
Step-by-step explanation:
Center c and a scale factor of 2
Hello there! The answer would be the first one, or No. At least one output results in two inputs.
When dealing with functions: you must remember that x does not repeat. So, lets look at the relation given, {(6, 1), (8, –3), (6, 7)}. You can see that x does repeat, so this is not a function. This eliminates second and fourth option choices. Out of the options A and C, A would be your choice since x is the input value and y is the output value, and there are two input values.
Hope his helps and have a great day!