Change 1/2 to a decimal with work shown

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

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

Acentral angle measuring 160 degrees intercepts an arc in a circle whose radius is 4. what is the length of the arc the circle formed by this central angle? round the length of the arc to the nearest hundredth of a unit. a) 4.19 units b) 6.28 units c) 12.57 units d) 12.57 square units