Expectation Maximization - question about the 2 different formulations of E-Step

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I saw the following 2 formulations for the E-Step:

$Q(θ,θ_t )=E_{θ_t} ( log(p_θ (X,Z))│X=x)$

$Q(θ,θ_t )= E_{Z|X,θ_t } [log(Pr_θ(X=x,Z))]$

I can't understand why they are equal.