Using linear functions, she pays the same for 10 classes, which is represented by the graph at the end of the question.
What is a linear function?
A linear function is modeled by:
y = mx + b
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.
For this problem, we consider the flat fee as the intercept and the cost per group class as the slope, hence the functions are given by:
She pays the same when:
A(x) = B(x).
70 + 3x = 40 + 6x
3x = 30
x = 10.
Hence when there are 10 classes.
More can be learned about linear functions at https://brainly.com/question/24808124
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