The inequality is
(Add 21 on each side)
(Apply Additive inverse property:
)
(Apply Additive identity property:
)
(Add:
)
(Divide each side by 7)
(Cancel common terms)
(Divide:
)
The solution set is
Graph the solution set on a number line.
Note: A circle means that this point is not included in the solution set.
The solution set is .
The graph is