X miles per hour - <span> speed of the boat in still water
(x - 2) - speed up the river
(x + 2) - speed down the river
</span>

=

30 * (x + 2) = 38 * (x - 2)
30x + 60 = 38x - 76
- 8x = - 136
x =
17 miles per hour - <span>
the speed of the boat in still water.</span>
Age of a dog (age is a number)
Answer:
205 yards
Step-by-step explanation:
One yard is 3 feet
Divide 615 feet by 3 to get 205
Answer:
Each book cost $37 dollars.
Step-by-step explanation:
351 - 18 = 333
333 ÷ 9 = 37