You can put this solution on YOUR website! find the equation of the circle with center on x+y=4 and 5x+2y+1=0, and whose radius is 3
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x+y=4
y=4-x
..
5x+2y+1=0
plug in (4-x) for y
5x+2(4-x)+1=0
5x+8-2x+1=0
3x+9=0
3x=-9
x=-3
y=4-x=4-(-3)=7
(-3,7)(point of intersection for given two lines)=coordinates of center of circle
Equation of circle: (x+3)^2+(y-7)^2=9