Initially 5 grams of salt are dissolved into 10 liters of water. brine with concentration of salt 5 grams per liter is added at a rate of 3 liters per minute. the tank is well mixed and drained at 3 liters per minute. let xbe the amount of salt, in grams, in the solution after t minutes have elapsed. find a formula for the rate of change in the amount of salt, dx/dt, in terms of the amount of salt in the solution x. dxdt=equation editorequation editorgrams/minutefind a formula for the amount of salt, in grams, after tminutes have elapsed. x(t)=equation editorequation editorgramshow long must the process continue until there are exactly 20 grams of salt in the tank?