can someone help me with part b?

A 41-gallon barrel contains a mixture with a concentration of 33% sodium chloride. You remove x gallons of this mixture and replace it with 100% sodium chloride. (a) Write the amount A of sodium chloride in the final mixture as a function of x. 1353 67x A(x ) = + 100 100 (b) Use a graphing utility to graph the concentration function. What is the domain of the function? ( Enter your answer using interval notation. ) (c) Approximate (accurate to one decimal place) the value of x when the final mixture is 60% sodium chloride. X = 16.5 gal