document.write( "Question 1103192: Phyllis invested 60000 dollars, a portion earning a simple interest rate of
\n" ); document.write( "5 percent per year and the rest earning a rate of 7 percent per year. After one year the total interest earned on these investments was
\n" ); document.write( "3420 dollars. How much money did she invest at each rate? \n" ); document.write( "

Algebra.Com's Answer #717902 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+I+\"$ = interest earned @ 5%
\n" ); document.write( " $\"+3420+-+I+\"$ = interest earned @ 7%
\n" ); document.write( "Let $\"+P+\"$ = Amount invested @ 5%
\n" ); document.write( " $\"+60000+-+P+\"$ = amount invested @ 7%
\n" ); document.write( "-----------------------------------------
\n" ); document.write( " $\"+I+=+P%2Ar%2At+\"$
\n" ); document.write( "(1) $\"++I+=+P+%2A.05%2A1+\"$
\n" ); document.write( "(2) $\"+3420+-+I+=+%28+60000+-+P+%29%2A.07%2A1+\"$
\n" ); document.write( "---------------------------------------
\n" ); document.write( "Plug (1) into (2)
\n" ); document.write( "(2) $\"+3420+-+.05P+=+4200+-+.07P+\"$
\n" ); document.write( "(2) $\"+.02P+=+780+\"$
\n" ); document.write( "(2) $\"+P+=+39000+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+60000+-+P+=+60000+-+39000+\"$
\n" ); document.write( " $\"+60000+-+P+=+21000+\"$
\n" ); document.write( "------------------------------
\n" ); document.write( "She invested $39,000 @ 5% and
\n" ); document.write( "$21,000 @ 7%
\n" ); document.write( "------------------------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+I+=+.05%2A39000+\"$
\n" ); document.write( "(1) $\"+I+=+1950+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+3420+-+I+=+21000%2A.07+\"$
\n" ); document.write( "(2) $\"+3420+-+I+=+1470+\"$
\n" ); document.write( "(2) $\"+I+=+1950+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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