Question 252307
In order to solve this, we need the quadratic equation which is {{{-b+-sqrt(b^2-4ac)}}} / {{{2a}}}.

step 1 - substitute what you know - -> (24 +- sqrt(24^2-4*9*?))/2(9)

we want only one solution, so the stuff under the sqrt, also called discriminant, must = 0.

step 2 ->  576 - 36? > = 0

solving for ? we get ? <= 16.

If ? = 16, our original equation is {{{9X^2 - 24X + 16}}}

which factors into {{{(3x-4)^2}}}. This is only one solution.