Create the equations by substituting the ordered pair for each point into the general form of the quadratic equation ax2 bx c. Simplify the right side of the equation. But here is how to come up with the quadratic formula.
You literally just substitute the numbers a for a b for b c for c and then it gives you two answers because you have a plus or a minus right there.
Add b2a 2 to both sides. 4a2x24abxb2-b2-4ac Take the -b2 to the right. Start with the usual quadratic equation. This is done by completing the square for the generic quadratic equation ax2 bx c 0.