Is 81x squared minus 1 a perfect square

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

What is the solution to the system of equation graphed belowa.(0,-4)b.(2,5),1),-3)

The measurement of one angle of a right triangle is 42° what is the measurement of the third angle? (there is no picture)