An inlet pipe can fill an empty swimming pool in 5hours, and another inlet pipe can fill the pool in 4hours. How long will it take both pipes to fill the pool?

It will take 2 hours, 13 minutes and 20 seconds for both pipes to fill the pool.

Step-by-step explanation:

Given that an inlet pipe can fill an empty swimming pool in 5hours, and another inlet pipe can fill the pool in 4hours, to determine how long it will take both pipes to fill the pool, the following calculation must be performed:

1/5 + 1/4 = X

0.20 + 0.25 = X

0.45 = X

9/20 = X

9 = 60

2 = X

120/9 = X

13,333 = X

Therefore, it will take 2 hours, 13 minutes and 20 seconds for both pipes to fill the pool.

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.