How do you solve 11x+9y_8z+4y_7x+7z

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?

The verbal translation for the difference of m and 7 increased by 15

Acircle has a radius of 12.6cm what is the exact length of an arc formed by a central angle measuring 120