Solve (question no. 2-22) for x :

$\dfrac{x - 8}{5} = \dfrac{x - 12}{9}$

$\dfrac{x - 8}{5} = \dfrac{x - 12}{9}$

On cross multiplying , we get :

⇒ (x - 8) $\times$ 9 = (x - 12) $\times$ 5

⇒ 9x - 72 = 5x - 60

⇒ 9x - 5x = - 60 + 72

⇒ 4x = 12

⇒ x = $\dfrac{12}{4}$

⇒ x = 3

Hence, the value of x is 3.