Problem B
Equation
Total = 3.50 + Number of movies watched * 0.45
Givens
Total = 17 movies.
Substitute and Solve.
Total = 3.50 + 17*0.45
Total = 3.50 + 7.65
Total = 11.15 Answer <<<<<
Conclusion: Stick with Netflix.
Problem A
Givens
Total = 7.10
Cost per movie = 0.45
Base Cost 3.50 for no movies.
Equation
Let the number of movies you can watch = n
Total = Base Cost + n*0.45
Substitute and solve
7.10 = 3.50 + n * 0.45 Subtract 3.50 from both sides.
7.10 - 3.50 = n*0.45
3.60 = n* 0.45 Divide by 0.45
3.60/0.45 = n
8 = n <<<< Answer
You can watch 8 movies.
Edit
Multiply both sides by 3.60
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You are done. It's like solving something like
3x + 4 = 13 You would subtract 4 first and then divide by 3