What is 1/7+2/3 fractions

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove

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?