Working together, two pumps can drain a certain pool in 4 hours. if it takes the older pump 9 hours to drain the pool by itself, how long will it take the newer pump to drain the pool on its own?

Number of hours newer pump needed to drain is given by

Step-by-step explanation:

Since we have given that

Number of hours taken by two pumps = 4 hours

Work done by two pumps =

Number of hours taken by older pump = 9 hours

Work done by older pump =

According to question, work done by new pump would be

So, Number of hours newer pump needed to drain is given by

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

answer: i'm great at algebra

~coco

step-by-step explanation: