Pls help brain list it's a big grade

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =

How do i take any fraction and make it into a decimal or percentage?

|2x - 6| > 10 {x|x < -8 or x > 2} {x|x < -2 or x > 8} {x|-2 < x < 8}