document.write( "Question 119871: The sum of two numbers is 15. Twice one number equoals three times the other. Find the numbers. \n" ); document.write( "

Algebra.Com's Answer #87846 by Earlsdon(6294) $\"\"$ $\"About$

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Let the two numbers be x and y.
\n" ); document.write( " $\"x%2By+=+15\"$ and...
\n" ); document.write( " $\"2x+=+3y\"$ rewrite this as: $\"x+=+%283%2F2%29y\"$ and substitute into the first equation.
\n" ); document.write( " $\"%283%2F2%29y%2By+=+15\"$ Combine like-terms.
\n" ); document.write( " $\"%285%2F2%29y+=+15\"$ Multiply both sides by the multiplicative inverse of $\"5%2F2\"$ which is $\"2%2F5\"$ .
\n" ); document.write( " $\"y+=+6\"$
\n" ); document.write( " $\"x+=+%283%2F2%29y\"$
\n" ); document.write( " $\"x+=+%283%2F2%29%286%29\"$
\n" ); document.write( " $\"x+=+9\"$
\n" ); document.write( "Check:
\n" ); document.write( " $\"x%2By+=+15\"$ Substitute x = 9 and y = 6.
\n" ); document.write( " $\"9%2B6+=+15\"$
\n" ); document.write( " $\"15+=+15\"$ OK, and...
\n" ); document.write( " $\"2x+=+3y\"$
\n" ); document.write( " $\"2%289%29+=+3%286%29\"$
\n" ); document.write( " $\"18+=+18\"$ OK \n" ); document.write( "

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