document.write( "Question 1114157: An investment of ​$39,000 was made by a business club. The investment was split into three parts and lasted for one year. The first part of the investment earned​ 8% interest, the second​ 6%, and the third​ 9%. Total interest from the investments was $ 3150.  The interest from the first investment was 4 times the interest from the second. Find the amounts of the three parts of the investment. \n" ); document.write( "
Algebra.Com's Answer #729191 by mananth(16946)\"\" \"About 
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An investment of ​$39,000 was made by a business club. The investment was split into three parts and lasted for one year.  Find the amounts of the three parts of the investment.\r
\n" ); document.write( "\n" ); document.write( "x+y+z=39000 ------------(1)\r
\n" ); document.write( "\n" ); document.write( "The first part (x)of the investment earned​ 8% interest,
\n" ); document.write( " the second​ (y) at 6%,
\n" ); document.write( " and the third​ (z) at 9%.\r
\n" ); document.write( "\n" ); document.write( " Total interest from the investments was $ 3150. 
\n" ); document.write( "8%x+6%y+9%z=3150
\n" ); document.write( "8x+6y+9z=315000 -----------(2)
\n" ); document.write( "The interest from the first investment was 4 times the interest from the second.
\n" ); document.write( "8%x= 4*6%y \r
\n" ); document.write( "\n" ); document.write( "8%x-24%y=0
\n" ); document.write( "8x-24y=0--------------------(3)\r
\n" ); document.write( "\n" ); document.write( "Solve the three equations\r
\n" ); document.write( "\n" ); document.write( "1 x + 1 y + 1 z = 39000
\n" ); document.write( "8 x + 6 y 9 z = 315000
\n" ); document.write( "
\n" ); document.write( "8 x + -24 y + 0 z 0
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\n" ); document.write( "consider equation 1 &2 Eliminate y
\n" ); document.write( "Multiply 1 by -6 1
\n" ); document.write( "Multiply 2 by 1 1
\n" ); document.write( "we get
\n" ); document.write( "-6 x + -6 y + -6 z = -234000
\n" ); document.write( "8 x + 6 y + 9 z = 315000
\n" ); document.write( "Add the two
\n" ); document.write( "2 x + 0 y + 3 z = 81000
\n" ); document.write( "consider equation 2 & 3 Eliminate y
\n" ); document.write( "Multiply 2 by 4
\n" ); document.write( "Multiply 3 by 1
\n" ); document.write( "we get
\n" ); document.write( "32 x + 24 y + 36 z = 1260000
\n" ); document.write( "8 x + -24 y + 0 z = 0
\n" ); document.write( "Add the two
\n" ); document.write( "40 x + 0 y + 36 z = 1260000 -------------5
\n" ); document.write( "Consider (4) & (5) Eliminate x
\n" ); document.write( "Multiply 4 by -20
\n" ); document.write( "Multiply (5) by 1
\n" ); document.write( "we get 2
\n" ); document.write( "-40 x + -60 z = -1620000
\n" ); document.write( "40 x + 36 z = 1260000
\n" ); document.write( "Add the two
\n" ); document.write( "0 x + -24 z = -360000
\n" ); document.write( "/
\n" ); document.write( "z = 15000
\n" ); document.write( "
\n" ); document.write( "Plug the value of z in (5)
\n" ); document.write( "40 x + 540000 = 1260000
\n" ); document.write( "40 x = 720000
\n" ); document.write( "x = 18000
\n" ); document.write( "plug value of x & z in 1
\n" ); document.write( "18000 + 1 y + 15000 = 39000
\n" ); document.write( "1 y = 39000 + -18000 + -15000
\n" ); document.write( " y= 6000 \r
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