The original function is
Write as
or
First solve the case .
Apply subtraction property of equality: if a = b, then a - c = b - c.
\ (Subtract 9 from each side)
(Additive inerse property:
)
(Additive identity property:
)
(Subtract:
)
Next solve the case .
(Subtract 9 from each side)
(Additive inerse property:
)
(Additive identity property:
)
(Subtract:
)
First, draw a number line.
\To graph the solutions set, mark the numbers –7 and –9 on number line.
\The solution set is .