help would be appreciated if u can solve it all i will be very thankful and i would like some hints too
$\displaystyle x^2 + y^2 - 2x - 4y - 4 = 0$
$\displaystyle (x^2 - 2x) + (y^2 - 4y) = 4$
Complete the square for both:
$\displaystyle (x^2 - 2x + 1) + (y^2 - 4y + 4) = 9$
Now we factor:
$\displaystyle (x - 1)^2 + (y - 2)^2 = 3^2$
Therefore, r = 3 and the center is $\displaystyle (1, 2)$