The inequlaity is .
Apply addition property of inequality: Add 9 to each side.
\ (Apply additive inverse property:
)
(Apply additive identity property:
)
(Add: 15 + 9 = 24)
Apply multiplication property of inequality: Multiply each side by 4.
\ (Cancel common terms)
(Multiply:
)
(Multiply each side by negative one and flip the symbol) \ \
(Product of two same signs is positive)
Check:
\To substitute a number less than or equal to in
.
(Substitute k =
)
(Product of two same signs is positive)
(Divide:
)
(Subtract:
)
The inequality is true
The inequality solution set is .