There are 13 books on your shelf, and you will take 5 of them on vacation with you. How many ways can the books be chosen?

What is the y intercept of f(x)=(1/2)^x?

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )