How do i solve this algebra problem: 2(4a-12)+3a=6a+1

Given that de, df, and ef are midsegments of △abc, and de=3.2 feet, ef=4 feet, and df=2.4 feet, the perimeter of △abc is .

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?

What is the circumference of the pie