Solution:
Consider the following equation:

this is equivalent to the following quadratic equation:

to solve this quadratic equation, we can apply the following quadratic formula:
![x\text{ = }\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}](https://img.qammunity.org/2023/formulas/mathematics/college/g6chm4j4qtch7yszwcwrt6mnkvwotsyyab.png)
here,
a = 1
b = -12
and
c = 27
so that, the solutions to the given quadratic equation are:
![x_1\text{ = }\frac{12+\sqrt[]{(-12)^2-4(1)(27)}}{2(1)}=\frac{12+\sqrt[]{36}}{2}=(12+6)/(2)=9](https://img.qammunity.org/2023/formulas/mathematics/college/7gkjvbvvl3xeu0obk57mcralmxc0ku1vua.png)
and
![x_2\text{ = }\frac{12-\sqrt[]{(-12)^2-4(1)(27)}}{2(1)}\text{ =}\frac{12-\sqrt[]{36}}{2}\text{= }(12-6)/(2)=3](https://img.qammunity.org/2023/formulas/mathematics/college/si4hfp19t7mt8yek5b9huow4h30ehn1rb3.png)
So that, the correct answer is:
the solutions are:
9 and 3.