Pls help i literally have no idea whats happening

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.

W-16=-12 solve each one step equation plz

Note: enter your answer and show all the steps that you use to solve this problem in the space provided. estimate 49% of 162. use mental math to calculate 49% of 162.