The easiest way to find the intercepts of this graph is by factoring. To factor a quadratic, we look for factors of the last number, that add up to the middle number. Below are the factors of the last number.
1 and 11
-1 and -11
Now we look for one that adds up to positive 12.
1 and 11
-1 and -11
Since these two add up to the middle number, we can use them in parenthesis with x + and factor. If there was not a pair, we would then have to use the quadratic equation.
f(x) = (x + 1)(x + 11)
Now to solve for the x-intercepts, we set each parenthesis equal to 0 and solve for x.
