Answer:
7 mph
Step-by-step explanation:
If b is the rate of the boat, and s is the rate of the stream, then:
b − s = 4
b + s = 10
Solve the system of equations with substitution or elimination. Using elimination, add the equations together:
2b = 14
b = 7
The boat's rate is 7 mph.
Answer:
s=7
p=3s
Step-by-step explanation:
The perimeter is the side length times 3
So the equation would be p=3s
Plug in 21 for p
21=3s
That means s=7
12 x 40 = hours she worked = 480
3 x 31 = appointment fee = 93
480 + 93 = 573