The quantities x and y are proportional. x y
4 10
55 12.5
10 25
Find the constant of proportionality (r) in the equation y=rx

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2

1. writing an equation for an exponential function by 2. a piece of paper that is 0.6 millimeter thick is folded. write an equation for the thickness t of the paper in millimeters as a function of the number n of folds. the equation is t(n)= 3. enter an equation for the function that includes the points. (-2, 2/5) and (-1,2)