The inequality is .
(Distributive property:
)
(Multiply:
)
(Commutative property:
)
(Subtract:
)
Apply subtraction property of inequality: Subtract 2 from each side.
\ (Additive inverse property:
)
(Additive identity property:
)
(Subtract:
)
(Divide each side by 2)
(Cancel common terms)
(Divide:
)
(Multiply each side by negative one and flip the symbol)
(Product of two same signs is positive)
Graph the solution set on a number line
Note: A dot means that this point is included in the solution set.
Check:
\To check, substitute a number 9
or greater than or equal to 9, in
.
(Substitute a =
9)
(Multiply:
)
(Product of two same signs is positive)
(Add:
)
(Multiply:
)
(Add:
)
The inequality is true.
The inequality solution set is .