document.write( "Question 581638: How do you solve the problem (1-4i)/(2+3i) \r
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Algebra.Com's Answer #371753 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "\"%281-4i%29%2F%282%2B3i%29\"\r\n" );
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document.write( "The denominator is 2+3i.  Its conjugate is 2-3i \r\n" );
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document.write( "(change the sign of the term containing i)\r\n" );
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document.write( "Multiply by the unit fraction formed by putting the con=jugate\r\n" );
document.write( "of the denominator over itself: \"red%28%282-3i%29%2F%282-3i%29%29\"\r\n" );
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document.write( "\"%281-4i%29%2F%282%2B3i%29\"·\"red%28%282-3i%29%2F%282-3i%29%29\"\r\n" );
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document.write( "\"%28%281-4i%29%282-3i%29%29%2F%28%282%2B3i%29%282-3i%29%29\"\r\n" );
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document.write( "Multiply (FOIL) out the top and bottom:\r\n" );
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document.write( "\"%282-3i-8i%2B12i%5E2%29%2F%284-6i%2B6i-9i%5E2%29\"\r\n" );
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document.write( "Combine the like terms. (the two middle terms in the bottom cancel)  \r\n" );
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document.write( "\"%282-11i%2B12i%5E2%29%2F%284-9i%5E2%29\"\r\n" );
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document.write( "Substitute (-1) for i²\r\n" );
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document.write( "\"%282-11i%2B12%28-1%29%29%2F%284-9%28-1%29%29\"\r\n" );
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document.write( "Simplify\r\n" );
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document.write( "\"%282-11i-12%29%2F%284%2B9%29\"\r\n" );
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document.write( "Combine like terms:\r\n" );
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document.write( "\"%28-10-11i%29%2F13\"\r\n" );
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document.write( "Divide the -10 and the -11 each by 13\r\n" );
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document.write( "\"%28-10%29%2F13+-+expr%2811%2F13%29i\"\r\n" );
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document.write( "\"-10%2F13+-+expr%2811%2F13%29i\"\r\n" );
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document.write( "Also, how would you find the equation of a circle with a diameter AB, given that the coordinates of a and B are (-6,1) and (4,-5). What is the answer in standard form:\r\n" );
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document.write( "We need the the radius r and the center (h,k) and then we can \r\n" );
document.write( "substitute thes is the equation for a circle:\r\n" );
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document.write( "(x - h)² + (y - k)² = r²\r\n" );
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document.write( "Let's graph the points and draw the diameter:\r\n" );
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document.write( "We will use the distance formula to find the diameter, which we will take\r\n" );
document.write( "on half of for the radius. The distance formula is:\r\n" );
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document.write( "d = \"sqrt%28%28x%5B2%5D-x%5B1%5D%29%5E2%2B%28y%5B2%5D-y%5B1%5D%29%5E2%29\"\r\n" );
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document.write( "d = \"sqrt%28%28%284%29-%28-6%29%29%5E2%2B%28%28-5%29-%281%29%29%5E2%29%29\" = \"sqrt%28%284%2B6%29%5E2%2B%28-5-1%29%5E2%29%29\" = \"sqrt%2810%5E2%2B%28-6%29%5E2%29%29\" = \"sqrt%28100%2B36%29\" = \"sqrt%28136%29\"\r\n" );
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document.write( "d = \"sqrt%284%2A34%29\" = \"sqrt%284%29sqrt%2834%29\" = \"2sqrt%2834%29\"\r\n" );
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document.write( "So the diameter is \"2sqrt%2834%29\" and the radius is one-half of that \r\n" );
document.write( "diameter which is \"sqrt%2834%29\"\r\n" );
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document.write( "The midpoint of any diameter is the center.  So we use the midpoint formula:\r\n" );
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document.write( "Midpoint =  = \r\n" );
document.write( " = \"%28matrix%281%2C3%2C++++++%28-6%2B4%29%2F2%2C+++%22%2C%22%2C+%281-5%29%2F2%29%29\" = \"%28matrix%281%2C3%2C++++++%28-2%29%2F2%2C+++%22%2C%22%2C+%28-4%29%2F2%29%29\" = \"%28matrix%281%2C3%2C++++++-1%2C+++%22%2C%22%2C+-2%29%29\"\r\n" );
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document.write( "So the center is (h,k) = C(-1,-2) and the radius is r = \"sqrt%2834%29\".\r\n" );
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document.write( "Substituting in\r\n" );
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document.write( "(x - h)² + (y - k)² = r²\r\n" );
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document.write( "(x - (-1))² + (y - (-2))² = (\"sqrt%2834%29\")²\r\n" );
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document.write( "(x + 1)² + (y + 2)² = 34\r\n" );
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document.write( "Edwin
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