What is the standard form of the equation below?

Solution:
we are given with the equation
[tex]x^2+y^2-2x-4y=4[/tex]
This equation can be written in the standard form as below
[tex]x^2-2\times x\times 1+1^2+y^2-2\times y \times 2+2^2-1^2-2^2=4\\\\(x-1)^2+(y-2)^2-5=4\\\\(x-1)^2+(y-2)^2=5+4\\\\(x-1)^2+(y-2)^2=9\\[/tex]
Hence the required equation in standrad form is [tex] (x-1)^2+(y-2)^2=9\\[/tex]