Answer:
m = number of minutes calls
Plan A : 30 + 0.15 m
Plan B: 16 + 0.20 m
For what amount of calling do the two plans cost the same?
30 + 0.15m = 16 + 0.20m
0.05m = 14
m = 280
280 minutes of calling, the two plans cost the same
What is the cost when the two plans cost the same?
Plan A: 30 + 0.15 m = 30 + 0.15 (280) = 72
Plan B: 16 + 0.20 m = 16 + 0.20 (280) = 72
It's cost $72 when the two plans cost the same