document.write( "Question 251662: ax+by=u
\n" ); document.write( "cx+d y=v when d is=[a b c d]=/0 what is the answer
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Algebra.Com's Answer #184425 by drk(1908)\"\" \"About 
You can put this solution on YOUR website!
I think I understand your question. Let's first solve for x and y in terms of a, b, c, d, u, and v.
\n" ); document.write( "multiply the first equation by c and the second equation by -a:
\n" ); document.write( "\"c%28ax+%2B+by+=+u%29\"
\n" ); document.write( "\"-a%28cx+%2B+dy+=+v%29\"
\n" ); document.write( "This will eliminate the x variable and we can solve for y.
\n" ); document.write( "\"cby+-+ady+=+cu+-+av\"
\n" ); document.write( "So, y equals
\n" ); document.write( "(i) \"+y+=+%28cu+-+av%29+%2F+%28bc+-+ad%29\"
\n" ); document.write( "substituting that into the first equation for x, we get
\n" ); document.write( "\"ax+%2B+b%28cu+-+av%29%2F%28bc-ad%29+=+u\"
\n" ); document.write( "Solving for x, we get
\n" ); document.write( "(ii) \"X+=+%28u+-+b%28%28cu+-+av%29%2F%28bc-ad%29%29%29%2Fa\"
\n" ); document.write( "Now we have solve for X and Y in terms of a, b, c, d, u, and v.
\n" ); document.write( "-----
\n" ); document.write( "Case 1: let d = a.
\n" ); document.write( "From (i and ii) we get
\n" ); document.write( "\"X+=+%28u+-+b%28%28cu+-+av%29%2F%28bc-a%5E2%29%29%29%2Fa\"
\n" ); document.write( "\"+y+=+%28cu+-+av%29+%2F+%28bc+-+a%5E2%29\"
\n" ); document.write( "-----
\n" ); document.write( "case 2: let d = b.
\n" ); document.write( "From (i and ii) we get
\n" ); document.write( "\"X+=+%28u+-+b%28%28cu+-+av%29%2F%28bc-ab%29%29%29%2Fa\" - -> \"X+=+%28u+-+%28%28cu+-+av%29%2F%28c-a%29%29%29%2Fa\"
\n" ); document.write( "\"+y+=+%28cu+-+av%29+%2F+%28bc+-+ab%29\"
\n" ); document.write( "-----
\n" ); document.write( "case 3: d = c.
\n" ); document.write( "From (i and ii) we get
\n" ); document.write( "\"X+=+%28u+-+b%28%28cu+-+av%29%2F%28bc-ac%29%29%29%2Fa\"
\n" ); document.write( "\"+y+=+%28cu+-+av%29+%2F+%28bc+-+ac%29\"
\n" ); document.write( "-----
\n" ); document.write( "case 4: d = d
\n" ); document.write( "From (i and ii) we get
\n" ); document.write( "\"X+=+%28u+-+b%28%28cu+-+av%29%2F%28bc-ad%29%29%29%2Fa\"
\n" ); document.write( "\"+y+=+%28cu+-+av%29+%2F+%28bc+-+ad%29\"\r
\n" ); document.write( "\n" ); document.write( "I hope that helps and is what you were looking for.\r
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