document.write( "Question 1070841: Two certificates of deposit pay interest at rates that differ by 4%. Money invested for one year in the first CD earns $270 interest. The same principal invested in the other CD earns $450. Find the two rates of interest. \n" ); document.write( "

Algebra.Com's Answer #685842 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+r+\"$ = rate of interest for 1st CD
\n" ); document.write( "Let $\"+P+\"$ = the principal for both CDs
\n" ); document.write( "---------------------------------------
\n" ); document.write( "(1) $\"+r%2AP+=+270+\"$
\n" ); document.write( "(2) $\"+%28+r+%2B+.04+%29%2AP+=+450+\"$
\n" ); document.write( "----------------------------
\n" ); document.write( "(1) $\"+P+=+270%2Fr+\"$
\n" ); document.write( "(2) $\"+%28+r+%2B+.04+%29%2A%28+270%2Fr+%29+=+450+\"$
\n" ); document.write( "(2) $\"+270+%2B+10.8%2Fr+=+450+\"$
\n" ); document.write( "(2) $\"+10.8%2Fr+=+180+\"$
\n" ); document.write( "(2) $\"+180r+=+10.8+\"$
\n" ); document.write( "(2) $\"+r+=+.06+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+r+%2B+.04+=+.1+\"$
\n" ); document.write( "The rate of interest for 1st CD is 6%
\n" ); document.write( "The rate of interest for 2nd CD is 10%
\n" ); document.write( "-------------------------------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+r%2AP+=+270+\"$
\n" ); document.write( "(1) $\"+P+=+270%2Fr+\"$
\n" ); document.write( "(1) $\"+P+=+270%2F.06+\"$
\n" ); document.write( "(1) $\"+P+=+4500+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+%28+r+%2B+.04+%29%2AP+=+450+\"$
\n" ); document.write( "(2) $\"+%28+.06+%2B+.04+%29%2AP+=+450+\"$
\n" ); document.write( "(2) $\"+.1P+=+450+\"$
\n" ); document.write( "(2) $\"+P+=+4500+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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