Question 304041
find the area of the circle whose equation is: x^2-4x+y^2+12y-25=0
(hint: the equation for a circle is (x-h)^2+(y-k)^2=r^2 where (h,k) is the center and r is the radius)
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{{{ x^2-4x+y^2+12y-25=0 }}}
Complete the square:
{{{ (x^2-4x+__) + (y^2+12y+__) = 25 }}}
{{{ (x^2-4x+4) + (y^2+12y+36) = 25+4+36 }}}
{{{ (x-2)^2 + (y+6)^2 = 65 }}}
From here we see that:
{{{r^2= 65 }}}
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{{{Area = (pi)r^2}}}
{{{Area = (3.14)(65)}}}
{{{Area = 204.1 }}} square units