Julie and eric row their boat (at a constant speed) 18 miles downstream for 3 hours by the current. rowing at the same rate, the trip back against the current takes 6 hours. find the rate of the boat in still water

the crews rowing rate is 6 mph and the rate of the current is 3 mph

Step-by-step explanation:

v the crew rowing rate

u rate of the current

downstream  v + u = 13.5/1.5 = 9 mph

upstream      v - u = 13.5/4.5 = 3 mph

u = 9 - v

v - ( 9 - v ) = 3

v - 9 + v = 3

2 v = 12

v 6 mph,   u 9 - 6 = 3 mph

so firstly, we need to isolate the y variables to be able to solve these inequalities. firstly, add 0.5x on both sides of the first inequality and subtract 1.5x on both sides of the second inequality:

now since the slope is positive for the first inequality, this means that the line going upwards belongs to the first inequality, and the line going downwards belongs to the second inequality.

next, since y ≥ in the first inequality, this means that the shaded region will be above the first inequality's line, thus shading regions a and b.

next, since y ≤ in the second inequality, this means that the shaded region is going to be below this line, thus shading regions a and c.

since both lines shade region a, this means that region a is the solution.

step-by-step explanation:

mark brainliest!