What is five times a number decreased by one in a algebraic expression

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.

Given that ot =5, xt=12, and ox= 13 is xy tangent to circle o at t? explain.

Solve x+3y=6 and 4x-6y=6 by elimination . show work !