Can someone explain how I answer this

Rewrite the following without an exponent. (5/8)-1

80 points suppose marcy made 45 posts online. if 23 of them contained an image, what percent of her posts had images? round your answer to the nearest whole percent. 54 percent 51 percent 49 percent 48 percent

Two numbers have a sum of -19. one number is x. what expression represents the other number?