Dominic earns 285 per week plus an 8% commission rate on all his sales. if dominic sell 4213 worth of merchandise in one week how much will his total earnings for the week be?

Regardless of his sales, Dom earns $285 per week.
He also earns 8% on all his sales, that is, 0.08($4213) = $337.04.

Add these two amounts together to obtain Dom's total income for this week.

Note that this is a linear equation.  If E = earnings for the week, then

E = $285 + 0.08($4213).  Looks like E=salary + commission.

The range would be 13 because you’re finding the difference