Me and i will give you anything in return

Aportion of a line bounded by two points is defined as

Yahir designs bracelets. he uses between 9 and 15 red and yellow beads in the ratio of 2 red bead to 5 yellow beads. drag the beads into the container to meet these requirements

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 =