I need the answers please

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

You decide instead to take the train there. the train will take 135 minutes. convert this into hours and minutes.

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?