Aphone company offers two monthly plans. plan a costs $30 plus an additional $0.15 for each minute of calls. plan b costs $16 plus an additional $0.20 for each minute of calls.
for what amount of calling do the two plans cost the same?
what is the cost when the two plans cost the same?

Lets 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

answer

It's cost $72 when the two plans cost the same