How to find function of x

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

Solve the problem by making up an equation. a man could arrive on time for an appointment if he drove the car at 40 mph; however, since he left the house 15 minutes late, he drove the car at 50 mph and arrive 3 minutes early for the appointment. how far from his house was his appointment?

Identify the slope an intercept of the following linear equation y = 1/5x - 6 a. slope: 1/5; intercept: -6 b. slope: 5; intercept: -6 c. slope: -1/5; intercept: 6 d. slope: 1/5; intercept: 6