Hi, can anyone verify if the equation below is correct?

$\displaystyle P(x = 5 | z_2 = 5, z_1 = 5) = \frac{P(z_2 = 5 | x = 5)P(x = 5 | z_1 = 5)}{P(z_2 = 5 | x = 5)P(x = 5 | z_1 = 5) + P(z_2 = 5 | x \neq 5)P(x \neq 5 | z_1 = 5)}$

If it is, I really don't understand where I'm going wrong with this exercise. If I am wrong, I'll have a followup question.