Need help with this math question

Question

Water flows into a tank according to the rate , and at the same time empties out at the rate , with both F(t) and E(t) measured in gallons per minute. How much water, to the nearest gallon, is in the tank at time t = 10 minutes. You must show your setup but can use your calculator for all evaluations.

Answer 1

If m(t) is mass of water in time t in gallons, then m.(t) = (t + 6)/((1 + t) - ln(t + 2)/(t + 1)

m(t) = ∫₀¹⁰[(t + 6)/(t + 1) - ln(t + 2)/(t + 1)]dt = 10.381 gallons