Question 1356
First lets look at the quadratic formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
So we get the a, b, and c from the standard form of a parabola equation
ax^2+bx+c
in this case, a=1, b=11, and c=18
Now we can use the quadratic formula:
{{{x = ((-11 +- sqrt( 11^2 - 4(1)(18)))/(2(1)))}}}
{{{x = ((-11 +- sqrt(49))/2)}}}
{{{x = (-11 +-7)/2}}}
x = -4/2 or -18/2
x = -2 or -9