Answer:(a)400min
(b)EZ plan
Explanation:
Given
For EZ plan cost $0.15 per minute
and Go Plan cost $40 + $0.05 per month
so for t minutes in a month both plan cost equals when
0.15t=40+0.05t
0.1t=40
t=400 minutes
for 400 minutes both cost equal.
(b)For 200 minutes
EZ plan cost
![200* 0.15=$30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g1ms8wquacl4ezw1v9vdbakgp4588rkv3u.png)
GO plan costs
![40+200* 0.05=40+10=$50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8gya62hs01g6vncwhf0u2dwu2tdn9xliok.png)
So for 200 minutes we can use EZ plan