The first pipe passes 4 liters of water per minute less than the second. How many liters of water

The first pipe passes 4 liters of water per minute less than the second. How many liters of water per minute does the second pipe pass if the reservoir with a volume of 672 liters fills 4 minutes faster than the first pipe

Let’s solve the problem using the equation.
Let the first pipe pass x liters per minute, then the second pipe lets (x + 4) liters per minute. We know that the 672 liter tank fills the second tube 4 minutes faster than the first tube. Let’s make the equation:
672 / x – 672 / (x + 4) = 4;
(672x + 2 688 – 672x) / (x ^ 2 + 4x) = 4;
2 688 / (x ^ 2+ 4x) = 4;
2 688 = 4 * (x ^ 2 + 4x);
4x ^ 2 + 16x – 2 688 = 0;
x ^ 2 + 4x – 672 = 0;
D = b ^ 2 – 4 * a * c = 16 + 2688 = 2 704;
x = (-4 + 52) / 2 = 24 liters per minute – the first pipe passes;
24 + 4 = 28 liters per minute – the first pipe passes.
Answer: 28 liters per minute.