if | x - 9 | = 3 x , then x = ?
"| x - 9 | = 3 x . . . ( given ) x ^ 2 - 18 x + 81 = 9 x ^ 2 8 * x ^ 2 + 18 * x - 81 = 0 . . . . ( by solving above eq . we get ) , x = - 4.5 or 2.25 = = = > ans - e"
subtract(add(3, 9), subtract(3, 9))