Answer:
5 messages/minute
Explanation:
If John sent 45 text messages in 9 minuites, the unit rate will be the amount of text messages sent in a minute
This can be expressed as;
45 text messages = 9minutes
x = 1 minute
where x is the unit rate
Cross multiply
9x = 45 * 1
9x = 45
x = 45/9
x = 5 messages/minute
Hence the unit rate is 5 messages/minute