PLEASE SUPER HELP

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab

If a flying disk is 139 meters in the air and travels at an average of 13 m/s how long is it in the air