Can someone help me pls

Given the sequence 7, 14, 28, 56, which expression shown would give the tenth term? a. 7^10 b. 7·2^10 c. 7·2^9

Ftara spends $219 a month for her car payment and she makes $3,200 a month, what percent of her monthly income is spent on her car payment?

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 =