Any way someone has a step by step process to solve for x?

-2x+9=21

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?

What is the binomial expansion of (2x-3)^5

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.