Answer:
Given,
The fixed charges = $ 2.10
Additional charges per miles = $ 0.80,
Thus, the additional charges for x miles = 0.80x dollars,
So, the total charges for x miles = Fixed charges + additional charges
= 2.10 + 0.80x
According to the question,
2.10 + 0.80x = 11.70
Which is the required equation,
Subtract 2.10 from both sides,
0.80x = 9.6
Divide both sides buy 0.80
x = 12
Hence, she travelled 12 miles.
