What expression has a value of 15 when x = 15

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Ascientist has discovered an organism that produces five offspring exactly one hour after its own birth, and then goes on to live for one week without producing any additional offspring. each replicated organism also replicates at the same rate. at hour one, there is one organism. at hour two, there are five more organisms. how many total organisms are there at hour seven? 2,801 19,531 19,607 97.655

Three people are traveling and need to exchange the currency of their native country for the currency of the country they are visiting. drag each exchange to the category that shows the ratio of currencies in that exchange.