Quick . i need to find x but i forgot the equation for this type of problem !

x = 3

Step-by-step explanation:

See the diagram attached.

We have a triangle Δ JMK and the line MB is a perpendicular drawn on JK from the vertex M.

Now, given that BJ = BK

Therefore, MB is the perpendicular bisector of side JK.

Hence, Δ JMK is a isosceles triangle with sides JM = MK

Hence, 9x - 18 = 3x {Since given that JM = 9x - 18 and MK = 3x}

⇒ 6x = 18

⇒ x = 3 (Answer)