What's the answer to this question because im having trouble

Solve the system by the elimination method. x + y - 6 = 0 x - y - 8 = 0 when you eliminate y , what is the resulting equation? 2x = -14 2x = 14 -2x = 14

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.

Hiroaki wants to find 3 3/4 - 7/8 explain why he must rename 3 3/4 to do the subtraction.