so basically you wanna think about what you know...she’s worked 4 hours, but she needs to get over 9 hours in order to get overtime.
we’re using x as the variable representing hours worked (other than the 4 hours already)
knowing this, we can set it up so that we have
4 + x > 9
and the. solve
4 + x -4 > 9 -4
x > 5
so this basically means that she needs to work over 5 more hours in order to earn overtime this shift
hope this helps :)