Solve and graph the solution set on a number line : -3x + 12 < -15; x ∈ R.
⇒ -3x + 12 < -15
⇒ -3x + 12 – 12 < -15 – 12
(Subtracting 12 from both sides)
⇒ -3x < -27
⇒ (-3x/-3) > (-27/-3) (Dividing both sides by -3)
Note: Division by a negative number reverses the inequality.
⇒ x > 9
∴ The required graph is :