If she charges $210 for the first 7 hours of tutoring, then for 7 hours our equation is A = 210.
Each additional hour past 7 hours is $20, so we have to find the number of hours past 7, h-7, and multiply it by the $20 charged.
A = 210 + 20(h - 7) ANSWER 1
If we plug in $410 as our A we can find the second answer.
410 = 210 + 20(h - 7)
200 = 20(h - 7)
10 = h - 7
17 = h ANSWER 2