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.

triangle and cube

step-by-step explanation:

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it