A manufacturer uses a tank to supply water to his machines while they are working. When the machines are on the tank loses 1.5 g
allons of water an hour at the same time 1 gallon of water is pumped into the tank from a well. Write an equation that models the amount of water (w) in the tank for any hour (h) that the machines are on. The tank starts full with 150 gallons of water in it.
OK. The first step is to find the amount the tank is losing per hour by balancing its gains and losses. Since it is gaining one gallon per hour but losing 1.5 gallons per hour, it is overall losing .5 gallons an hour. If there was originally 150 gallons in the tank, you can use the equation w=-.5h+150 to find the amount of water after h hours.
![\bf 1050=1020\left[ 1+r\left( \frac{3}{2} \right) \right]\implies \cfrac{1050}{1020}=1+r\left( \frac{3}{2} \right) \implies \cfrac{35}{34}=1+r\left( \frac{3}{2} \right) \\\\\\ \cfrac{35}{34}-1=\cfrac{3}{2}r\implies \cfrac{1}{34}=\cfrac{3}{2}r\implies \cfrac{2\cdot 1}{3\cdot 34}=r\implies \cfrac{1}{51}=r \\\\\\ r\%=100\cdot \cfrac{1}{51}\implies r\approx\stackrel{\%}{1.96078431372549}](https://tex.z-dn.net/?f=%5Cbf%201050%3D1020%5Cleft%5B%201%2Br%5Cleft%28%20%5Cfrac%7B3%7D%7B2%7D%20%5Cright%29%20%5Cright%5D%5Cimplies%20%5Ccfrac%7B1050%7D%7B1020%7D%3D1%2Br%5Cleft%28%20%5Cfrac%7B3%7D%7B2%7D%20%5Cright%29%20%5Cimplies%20%5Ccfrac%7B35%7D%7B34%7D%3D1%2Br%5Cleft%28%20%5Cfrac%7B3%7D%7B2%7D%20%5Cright%29%0A%5C%5C%5C%5C%5C%5C%0A%5Ccfrac%7B35%7D%7B34%7D-1%3D%5Ccfrac%7B3%7D%7B2%7Dr%5Cimplies%20%5Ccfrac%7B1%7D%7B34%7D%3D%5Ccfrac%7B3%7D%7B2%7Dr%5Cimplies%20%5Ccfrac%7B2%5Ccdot%201%7D%7B3%5Ccdot%2034%7D%3Dr%5Cimplies%20%5Ccfrac%7B1%7D%7B51%7D%3Dr%0A%5C%5C%5C%5C%5C%5C%0Ar%5C%25%3D100%5Ccdot%20%5Ccfrac%7B1%7D%7B51%7D%5Cimplies%20r%5Capprox%5Cstackrel%7B%5C%25%7D%7B1.96078431372549%7D)
