ANSWER:
x = 6; 7
STEP-BY-STEP EXPLANATION:
We have the following equation:
[tex]\sqrt{x-6}=x-6[/tex]
We solve for x:
[tex]\begin{gathered} \left(\sqrt{x-6}\right)^2=\left(x-6\right)^2 \\ \\ x-6=x^2-12x+36 \\ \\ x^2-12x-x+36+6=0 \\ \\ x^2-13x+42=0 \\ \\ -13x=-6x-7x \\ \\ x^2-6x-7x+42=0 \\ \\ \left(x^2-6x\right)+\left(-7x+42\right)=0 \\ \\ x\left(x-6\right)-7\left(x-6\right) \\ \\ \left(x-6\right)\left(x-7\right)=0 \\ \\ x-6=0\rightarrow x=6 \\ \\ x-7=0\operatorname{\rightarrow}x=7 \\ \\ \text{ We check each solution, as follows:} \\ \\ \sqrt{6-6}=6-6\rightarrow0=0\rightarrow\text{ True} \\ \\ \sqrt{7-6}=7-6\rightarrow1=1\rightarrow\text{ True} \\ \\ \text{ Both solutions are correct therefore:} \\ \\ x=6;7 \end{gathered}[/tex]
