Let \( f \) be a differentiable function in the interval \( (0, \infty) \) such that \( f(1) = 1 \) and \( \lim_{t \to x} \frac{t^{2} f(x) - x^{2} f(t)}{t - x} = 1 \) for each \( x > 0 \). Then \( 2 f(2) + 3 f(3) \) is equal to ____________.
