For this case we have the following equation:
[tex]81x = x ^ 2[/tex]
Rewriting we have:
[tex]x ^ 2-81x = 0[/tex]
We take common factor "x" from both terms:
[tex]x (x-81) = 0[/tex]
It is observed that equality is fulfilled when x = 0 and when x = 81
So, the roots are:
[tex]x_ {1} = 0\\x_ {2} = 81[/tex]
Answer:
[tex]x_ {1} = 0\\x_ {2} = 81[/tex]
