Find the missing number of each unit rate? 6/3= ? /1 and 30/10 ? /1

Given that de, df, and ef are midsegments of △abc, and de=3.2 feet, ef=4 feet, and df=2.4 feet, the perimeter of △abc is .

The revenue each season from tickets at the theme park is represented by t(c)=5x. the cost to pay the employees each season is represented by r(x)=(1.5)^x. examine the graph of the combined function for total profit and estimate the profit after four seasons

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).