There are 19 finalists in a singing competition. The top four singers receive prizes. How many ways can the singers finish first through fourth​?

Television sizes are based on the length of the diagonal of the television's rectangular screen. so, for example, a 70-inch television is a television having a diagonal screen length of 70 inches. if a 70 inch television's diagonal forms a 29°angle with the base of the screen, what is the vertical height (1) of the screen to the nearest inch? 70 inhin

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)