What does coefficient in math mean?

Which of the following statements would be sufficient to prove that parallelograms pqrs is a rectangle ?

Solve the equation for y. -1 = 1/3y + 11. will give 5 stars if answered correctly!

Abusiness plan is centered around a circular area of distribution. the plan calls for the radius of the distribution to increase 50 miles per year. the investors have asked that the plan include a reference to the area of distribution based on the number of years in business. these functions model this plan: radius in y years: r(y) = 50y total area: a(r) = πr2; r in miles what is a(r( the total area in y years? a(r(y)) = 50πy2 a(r(y)) = 2,500πy2 a(r(y)) = 50πr2 a(r(y)) = 2,500πr2