8.  a tourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.

  3 mph

Step-by-step explanation:

Let c represent the current of the river in miles per hour. Then the ratio of speed downstream to speed upstream is ...

  (21 +c)/(21 -c) = 2.4/1.8

  1.8(21 +c) = 2.4(21 -c) . . . . . . multiply by 1.8(21-c)

  37.8 + 1.8c = 50.4 -2.4c . . . . eliminate parentheses

  4.2c = 12.6 . . . . . . . . . . . . . . . add 2.4c-37.8

  c = 3 . . . . . . . . . . . . . . . . . . . .divide by 4.2

The current of the river is 3 miles per hour.

no, the equation would be invalid since they are both not equal.

step-by-step explanation:

here you got

4y-6+4y 2-9

first, you would simplify the equation on the form.

4y-6+4y 2-9

then, move all the terms that contains a y to the left and all the other terms to the right.

+4y-4y+-9-6

finally, you will simplify the left and the right side of the equation.

y=-3

part 1 answer = 8

part 2 answer = 72

step-by-step explanation:

part 1 explanation = add all of the numbers, then divide by how many numbers you have. so, 200/25 = 8.

part 2 explanation = not gonna lie, this is hard to explain, so just google how to do it.