Amount earned by Sharon per item sold = $25
Base salary of Sharon per week = $100
Amount that needs to be earned by Sharon per week = 975
Let us assume the number of items sold by Sharon per week = x
Then
100 + 25x = 975
25x = 700 - 100
25x = 600
x = 600/25
= 24
So Sharon needs to sell 24 items to earn a total of 975 per week. I hope you have understood the method of solving such problems.
I think I got confused with another problem? Let me know if I'm wrong