I need help ASAP
Geometry​

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Acircle has a circumference of 7.850 units. what is its radius?

Jenny earned a 77 on her most recent test jenny score is no less then 5 points greater then 4/5 of terrance’s score if t represents terrance score which inequality represents the situation