Simplify radical expression with variables. please helping super confused

What is the value of x in the diagram below?

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?

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2