2x + 7 + x -1 = 12 – x + 2

Will give brainliest if you answer question correct

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?

Empty box + box + empty box fill in the box is equal to 30 how