only the last question(148), please explain step by step. thanks

For the following exercises, find the volume generated when the region between the curves is rotated around the given axis. 140. y = 3- x, y = 0, x = 0, and x - 2 rotated around the y-axis. 141. y = x , I = 0, and y = 8 rotated around the y-axis. 142. y - 34, y = , rotated around the y-axis. 143. y - Vc, y = 0, and x = 1 rotated around the line x = 2. 144. y = 7 2 = 1, x = 2 and y = 0 rotated around the line c = 4. 145. y = va and y = " rotated around the y-axis. 146. y =\\ and y = x rotated around the line x = 2. 147.a y , = -, = = 1, and x = 2 rotated around the x-axis. 148. = y and y = @ rotated around the line y = 2