What is one dimensional and have infinite length

If the class was going to get a class pet and 5 picked fish and 7 pick bird and 8 picked rabbits have many students were in the

Aye asap pls ! markin da brainiest too ! btw da step choices are all add, distribute, divide, n subtract

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 =