Question 574673
How to use the quadratic formula {{{x = (-b+-sqrt(b^2-4ac))/2a}}}for solving:
{{{3x^2-6x-7 = 0}}}
First, identify a, b, and c from the quadratic equation.
These come from the general form: {{{ax^2+bx+c = 0}}} so in your problem, a = 3, b = -6, and c = -7.
Substitute these values into the formula:
{{{x = (-(-6)+-sqrt((-6)^2-4(3)(-7)))/2(3)}}} Simplify this.
{{{x = (6+-sqrt(36-(-84)))/6}}} Evaluate.
{{{x = (6+-sqrt(120))/6}}}
{{{x = 6/6 +sqrt(120)/6}}} or {{{6/6-sqrt(120)/6}}}
{{{x = 1+1.826}}} or {{{x = 1-1.826}}}
{{{x = 2.826}}} or {{{x = -0.826}}}