Question 86765
You are almost absolutely correct! The two in your answer should be negative.
Starting with:
{{{x^2 + 4x + 4 = 7}}} Subtract 7 from both sides to get your equation into the standard form:{{{ax^2+bx+c = 0}}}
{{{x^2+4x-3 = 0}}} Applying the quadratic formula: {{{x = (-b+-sqrt(b^2-4ac))/2a}}} you'll get:
{{{x = (-4+-sqrt(4^2-4(1)(-3)))/2(1)}}} Simplifying this:
{{{x = (-4+-sqrt(16-(-12)))/2}}}
{{{x = (-4+-sqrt(28))/2}}} Simplifying further:
{{{x = (-4+-sqrt(4*7))/2}}}
{{{x = (-4+-2*sqrt(7))/2}}} This should show + or -
{{{x = -2+sqrt(7)}}} or {{{x = -2-sqrt(7)}}}