What is the solution for a + 9 = 4a

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

3women sell hats at a craft fair weekly. the money they make at the fair is split into categories. 9% goes to pay taxes. $55 goes to pay rent for the space they sell in. the rest is split between the women. if the group make $706 at the fair, how much does each women get paid once the money is divided