Find the constant of proportionality (r) in the equation y=rx

Celeste wants to have her hair cut and permed and also go to lunch. she knows she will need $50. the perm cost twice as much as her haircut and she needs $5 for lunch. how much does the perm cost?

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent

If you invest 1,500 today in a bank that gives you a 5 percent annual interest rate, which of these items can you buy in two years? a. electronics worth $1,650 b.fitness equipment worth $1,700 c.a holiday package worth $2,000