Question 269446
here is the original problem
(i) {{{(x+3)(x-9)= -13 }}}
step 1 - foil out the left side to get
(ii) {{{x^2 - 6x - 27 = -13}}}
step 2 - set the equation = 0 to get
(iii) {{{x^2 - 6x - 14 = 0}}}
step 3 - factor if possible. IN this case, we cannot apply our factoring steps as usual, so we must use the quadratic as
{{{x = (6 +- sqrt(36-4*1*(-14)))/(2)}}}
or
{{{x = (6 +- sqrt(92))/(2)}}}
and then
{{{x = (6 +- 2sqrt(23))/(2)}}}
finally
{{{x = 3 +- sqrt(23)}}}