Can someone please help me solve this. You need to find the missing numbers

In which source of water would a wave travel the fastest? o ice o cold o room temperature o hot mark this and return save and exit next

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

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?