f p, q, and r are rational numbers, which of the following equations is/are true?

I) p × (q + r) = (p × q) + (p × r)
II) p × (q - r) = (p × q) - (p × r)
III) p × (q × r) = (p × q) × (p × r)
IV) p + (q × r) = (p + q) × (p + r)