Given lines are 3x + 4y = 9 and 6x + 8y = 18 To Find: Distance between the lines 6x + 8y = 18 ⇒ 6x + 8y - 18 = 0 Take 2 common from above equation, we get ⇒ 3x + 4y - 9 = 0 .... (1) And 3x + 4y - 9 = 0 .... (2) Equation 1 and 2 are parallel to each other. ∴ The distance between the lines =