Answer:
Step-by-step explanation:
Recall your d = rt, distance = rate * time.
now, if the boat has a speed of say "b", and the current has a speed of say "c", when the boat is going upstream, is not really going "b" fast, is going " b - c " fast, because the current is eroding speed from it, going upwards.
And when the boat is going downstream, is not going "b" fast either, because the current is now adding to speed to it, so is really going " b + c " fast.
The time it took one way, is the same time it took back, 4 hours each way.
thus

what's the speed of the boat? well, 5 + c = b.
Answer:
Part 1)
-----> 
Part 2)
------> 
Part 3)
-----> 
Part 4)
-----> 
Part 5)
------> 
Step-by-step explanation:
Part 1) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Convert to mixed number

Part 2) we have

To calculate the subtraction eliminate the parenthesis first

Part 3) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Eliminate the parenthesis

Convert to mixed number

Part 4) we have

To calculate the subtraction eliminate the parenthesis first

Part 5) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Eliminate the parenthesis

No its not am sure its not