90 is the largest integer
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>
9x-3x-5-3=2x-12
12x -8 =2x-12
-2x. -2x
10x. -8. =-12
+8. +8
10x. = -4
X = -0.4
There are 18 girls in the class and 6 boys.