How do you put 7/8 into a decimal

Plzzz answer both questions and i will give you 100 points

If 5x - 2 = -12, then x = a) -50 b) -4.4 c) -2.8 d) -2

The interior angles formed by the sides of a hexagon have measures that sum to 720°. what is the measure of angle a? enter your answer in the box. m∠a= °