Let last weeks pay = x
This week she earned 15% more so she earned 100% + 15% more for 115% total.
Setup an equation:
115% times x = $225
115% as a decimal = 1.15
So the equation is:
1.15x = 225
Solve for x by dividing both sides by 1.15:
X = 225/1.15
X = 195.65
Last week she earned $195.65
