I need solve

Question 3 (15+15 points) a) If the the average value of the function g(x) = 2 + 6x - 317 over the interval [0, b] is given as 4, then find the possible value of the number b. b) Consider the region R enclosed by y = 4 - (1 - 2) and 3y -3x-6 -0. Find the volume of the solid obtained by the rotation of the region R about the z-axis. Provide a sketch for the region R