It takes 2 hours for a boat to travel 28 miles downstream. the same boat can travel 18 miles upstream in 3 hours .find the rate of the stream's current.

  4 mph

Step-by-step explanation:

The speed downstream is (28 mi)/(2 h) = 14 mph.

The speed upstream is (18 mi)/(3 h) = 6 mph.

The speed of the current is half the difference of these:

  (14 mph -6 mph)/2 = 4 mph

The current adds to the downstream speed and subtracts from the upstream speed, so the difference of those speeds is twice the current's speed.

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.  

step-by-step explanation:

compare