Answer:
Blank 1: 40
Blank 2: 10
Explanation:
You can start by representing the speed of the water as x and the speed of the dolphin as y, and writing an equation.
y+x=50
y-x=30
Adding these two equations together, you get:
2y=80
y=40 for the speed of the dolphin in still water. Now, you an use one of the previous equations to find the speed of the current.
40-x=30
x=10
Hope this helps!