document.write( "Question 1119612: Hi, these are five questions which I need help in
\n" ); document.write( "Write the general equation for the circle that passes through the points:
\n" ); document.write( "(1, 7)
\n" ); document.write( "(8, 6)
\n" ); document.write( "(7, -1)
\n" ); document.write( "Write the general equation for the circle that passes through the points (1, 1), (1, 3), and (9, 2).
\n" ); document.write( "Write the general equation for the circle that passes through the points (- 5, 0), (0, 4), and (2, 4).
\n" ); document.write( "Write the general equation for the circle that passes through the points:
\n" ); document.write( "(-1, 2)
\n" ); document.write( "(4, 2)
\n" ); document.write( "(- 3, 4)
\n" ); document.write( "Write the general equation for the circle that passes through the points:
\n" ); document.write( "(0, 0)
\n" ); document.write( "(6, 0)
\n" ); document.write( "(0, - 8) \n" ); document.write( "
Algebra.Com's Answer #735197 by Boreal(15235)\"\" \"About 
You can put this solution on YOUR website!
For the last one
\n" ); document.write( "(x-a)^2+(y-b)^2=r^2
\n" ); document.write( "For the origin, x and y are 0 so a^2+b^2=r^2
\n" ); document.write( "For (6, 0) (6-a)^2+(0-b^2)=r^2 and 36-12a+a^2+b^2=r^2
\n" ); document.write( "But since r^2=a^2+b^2
\n" ); document.write( " 36-12a+a^2+b^2=a^2+b^2
\n" ); document.write( "12a=36 and a=3
\n" ); document.write( "similarly, for (0, -8) we have a^2+64+16b+b^2=a^2+b^2 and -16b=-64 and b=-4
\n" ); document.write( "The center is at (3, -4) and the radius is sqrt((-3)^2+4^2)=5
\n" ); document.write( "(x-3)^2+(y+4)^2=25\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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