Recall your d = rt, distance = rate * time.
b = speed rate of the boat.
c = speed rate of the current.
keeping in mind that, as the boat goes Upstream, against the current, it's speed is not "b", but is really " b - c ", because the current is subtracting speed from it.
likewise, when the boat is going Downstream, because is going with the current, is really going faster at " b + c ".

what is the speed of the boat? well, 61 + c = b.
The answer is D. x=0 and x=4 because a way to determine the answer is by inputting all the choices for x they have and if any of them has the answer then choose that one
Answer:
please mark me brainliesf if it helps you
f(x) = -3x+1
or, y = -3x + 1
Interchanging the position of x and y, we get,
x = -3y +1
or, 3y = 1 - x
or, y = 1 - x /3
: . f^-1(x) = 1-x / 3