Answer: There is difference of $660 in their paychecks.
Step-by-step explanation:
Since we have given that
Number of hours in one week they worked = 40
Amount of sales = $78000
Kent makes $10 per hour plus 3% on the amount of sales .
So, the equation for Kent becomes,

Similarly, Bradley only makes $7 per hour but he makes 4% on the amount of his sales .
So, the equation for Bradley becomes,

hence, the difference between of their paychecks is given by

Therefore, there is difference of $660 in their paychecks.