The inequality is .
Apply addition property of inequality: Add 6 to each side.
\
(Commutative property: a+b=b+a)
(Add:
)
(Additive inverse property:
)
(Additive identity property:
)
(Subtract 3b from each side )
(Subtract:
)
(Additive inverse property:
)
(Subtract 21 from each side )
(Commutative property: a+b=b+a)
(Subtract:
)
(Additive inverse property:
)
(Additive identity property:
)
(Divide each side by 21)
(Divide:
)
(Cancel common terms )
Graph the Solution set on a number line
\ (Note: A dot means that this point is included in the solution set)
The solution set is .