Final answer:
Heather sent 600 texts during the month of September, which is determined by solving the equation 30 + 0.05x = 60, where x represents the number of texts sent.
Step-by-step explanation:
The question asks us to determine the number of texts (x) that Heather sent in September knowing that her cell phone bill was $60 and that she pays $30 per month plus $0.05 per text. To find x, we set up the following equation:
30 + 0.05x = 60
First, we subtract $30 from both sides of the equation to get:
0.05x = 30
Then, we divide both sides by 0.05 to find the number of texts sent:
x = 30 / 0.05
x = 600
Therefore, Heather sent 600 texts during the month of September.