How to solve (x+7)(x-9)>0

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.

The table above shows approximate conversions from gallons to liters. what is the value of x?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?