Solve triangles using the law of sines

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

How do you use the elimination method for this question? explain, because i really want to understand!

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?