document.write( "Question 180221: please help with this problem.
\n" ); document.write( "
\n" ); document.write( "Suppose you have recieved a total of $1,520 a year in interest from three investments. The interest rates for the investments are 5%, 7%, and 8%. The amount is invested at 5% is half of the amount invested at 7%. The amount invested at 7% is $1,500 less than the amount invested at 8% Find the amount of money invested at each rate.
\n" ); document.write( "
\n" ); document.write( "Thank you!
\n" ); document.write( "

Algebra.Com's Answer #135068 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Suppose you have received a total of $1,520 a year in interest from three investments. The interest rates for the investments are 5%, 7%, and 8%. The amount is invested at 5% is half of the amount invested at 7%. The amount invested at 7% is $1,500 less than the amount invested at 8% Find the amount of money invested at each rate.
\n" ); document.write( "----------------
\n" ); document.write( "Let \"x\" be amt invested at 5%
\n" ); document.write( "Let \"y\" be amt. invested at 7%
\n" ); document.write( "Let \"z\" be amt. invested at 8%
\n" ); document.write( "-------------------------------------
\n" ); document.write( "Interest Equation: 0.05x + 0.07y + 0.08z = 1520
\n" ); document.write( "Quantity Equation: x = (1/2)y
\n" ); document.write( "Quantity Equation: y = z - 1500
\n" ); document.write( "--------------------------
\n" ); document.write( "Write x and z interms of y:
\n" ); document.write( "x = (1/2)y
\n" ); document.write( "z = y + 1500
\n" ); document.write( "--------------------------------------------------------
\n" ); document.write( "Substitute into the 1st equation to solve for \"y\":
\n" ); document.write( "0.05((1/2)y) + 0.07y + 0.08(y+1500) = 1520\r
\n" ); document.write( "\n" ); document.write( "Multiply thru by 100 to get:
\n" ); document.write( "5(1/2)y + 7y + 8(y + 1500) = 152000\r
\n" ); document.write( "\n" ); document.write( "(5/2)y + 7y + 8y + 12000 = 152000
\n" ); document.write( "(35/2)y = 140000
\n" ); document.write( "y = $8000.00 (amt. invested at 7%)
\n" ); document.write( "----------
\n" ); document.write( "x = (1/2)y = $4000.00 (amt. invested at 5%)
\n" ); document.write( "----------
\n" ); document.write( "z = y + 1500 = $9500 (amt. invested at 8%)
\n" ); document.write( "-----------------------------------------------------
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );