Question 1007972
Simplify it first because less work that way.


{{{x^2-8x+70=0}}}


Can you factor the left member?  If not, study, understand, and apply this lesson:
<a href="http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev">Solve a Quadratic Equation - Includes how to Complete The Square</a>.