Which one do you need help on
Recall your d = rt, distance = rate * time.
b = speed rate of the boat.
c = speed rate of the current.
keeping in mind that, as the boat goes Upstream, against the current, it's speed is not "b", but is really " b - c ", because the current is subtracting speed from it.
likewise, when the boat is going Downstream, because is going with the current, is really going faster at " b + c ".

what is the speed of the boat? well, 61 + c = b.
Answer:21
Step-by-step explanation:9+10=21
Answer:
29
Step-by-step explanation:
As it is a list of prime number, the sequence continues with 29 being the next prime number after 23.
Yes and no. A negative number and it's opposite are 'integers.' Yes, a negative and a negative multiplied together give you a positive. The two negative signs cancel out making it positive. But no, a positive and a positive multiplied together do not give you a negative. When you subtract positive numbers you can get a negative, but not when multiplying. If you were to do a positive times a negative it would be negative because the positive can't cancel it out. Example: -3 · -3 = 9. [] 3 · 3 = 9. [] -3 · 3 = -9. Other than the positive number part, the statement is true about the negatives. I hope that helped!