document.write( "Question 672095: Can you solve the following problem: \"Sponge Bob needs to make $1000 interest by investing $15,000. Some will be invested at 4% and the rest at 7%. How much should he invest at each rate?\" My son was given this on an Algebra worksheet. He has other similar problems. I would like to see all the work so that we may solve the other problems. Thank you, Cyndi \n" ); document.write( "

Algebra.Com's Answer #417806 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
I will assume that the investments are for 1 year.
\n" ); document.write( "Let $\"+x+\"$ = the amount invest at 4%
\n" ); document.write( "Then $\"+15000+-+x+\"$ will be the amount invested at 7%
\n" ); document.write( " $\"+1000+=+.04x+%2B+.07%2A%28+15000+-+x+%29+\"$
\n" ); document.write( " $\"+1000+=+.04x+%2B+1050+-+.07x+\"$
\n" ); document.write( " $\"+.03x+=+1050+-+1000+\"$
\n" ); document.write( " $\"+.03x+=+50+\"$
\n" ); document.write( " $\"+x+=+1666.67\"$
\n" ); document.write( " $\"+15000+-x+=+15000+-+1666.67+\"$
\n" ); document.write( " $\"15000+-+x+=++13333.33+\"$
\n" ); document.write( "He should invest $1,666.67 @4% and
\n" ); document.write( "$13,333.33 @ 7%
\n" ); document.write( "----------------
\n" ); document.write( "check answer
\n" ); document.write( " $\"+1000+=+.04x+%2B+.07%2A%28+15000+-+x+%29+\"$
\n" ); document.write( " $\"+1000+=+.04%2A1666.67+%2B+.07%2A13333.33+\"$
\n" ); document.write( " $\"+1000+=+66.6667+%2B+933.3333+%5D%5D%5D%0D%0A%7B%7B%7B+1000+=+1000+\"$
\n" ); document.write( "OK\r
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