document.write( "Question 1205323: Siti has RM450000 in her ASB. She wants to invest in Gading Mutual deposit, Maju
\n" ); document.write( "Makmur bar gold, Indah certificate deposit and Selamat Maju bar gold which pay
\n" ); document.write( "simple annual interest of 9%, 6%, 10% and 15%, respectively. Moreover, she wants
\n" ); document.write( "to combine annual return of 8% and want to have only one-third of investment in
\n" ); document.write( "Indah certificate deposit and Selamat Maju bar gold.
\n" ); document.write( "a. Write the linear model system equation for the whole investment.
\n" ); document.write( "c. Use elimination method to find each of the investment
\n" ); document.write( "

Algebra.Com's Answer #847957 by CPhill(1987)\"\" \"About 
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## Setting up the Linear Model\r
\n" ); document.write( "\n" ); document.write( "**Let's denote:**
\n" ); document.write( "* **G:** Amount invested in Gading Mutual Deposit
\n" ); document.write( "* **M:** Amount invested in Maju Makmur Bar Gold
\n" ); document.write( "* **I:** Amount invested in Indah Certificate Deposit
\n" ); document.write( "* **S:** Amount invested in Selamat Maju Bar Gold\r
\n" ); document.write( "\n" ); document.write( "**Based on the given information, we can set up the following system of linear equations:**\r
\n" ); document.write( "\n" ); document.write( "1. **Total Investment:** G + M + I + S = 450000
\n" ); document.write( "2. **Total Annual Return:** 0.09G + 0.06M + 0.10I + 0.15S = 0.08 * 450000
\n" ); document.write( "3. **Indah and Selamat Maju Investment:** I + S = (1/3) * 450000\r
\n" ); document.write( "\n" ); document.write( "## Solving the System Using Elimination Method\r
\n" ); document.write( "\n" ); document.write( "**Step 1: Simplify the Equations**
\n" ); document.write( "* Equation 2: 9G + 6M + 10I + 15S = 360000
\n" ); document.write( "* Equation 3: I + S = 150000\r
\n" ); document.write( "\n" ); document.write( "**Step 2: Eliminate a Variable**
\n" ); document.write( "* Let's eliminate S. From Equation 3, we can express S as:
\n" ); document.write( " * S = 150000 - I
\n" ); document.write( "* Substitute S in Equations 1 and 2:
\n" ); document.write( " * Equation 1: G + M + I + (150000 - I) = 450000
\n" ); document.write( " => G + M + 150000 = 450000
\n" ); document.write( " * Equation 2: 9G + 6M + 10I + 15(150000 - I) = 360000
\n" ); document.write( " => 9G + 6M - 5I = -750000\r
\n" ); document.write( "\n" ); document.write( "**Step 3: Simplify the Equations Further**
\n" ); document.write( "* Equation 1: G + M = 300000
\n" ); document.write( "* Equation 2: 9G + 6M - 5I = -750000\r
\n" ); document.write( "\n" ); document.write( "**Step 4: Eliminate Another Variable**
\n" ); document.write( "* Let's eliminate M. Multiply Equation 1 by -6 and add it to Equation 2:
\n" ); document.write( " * -6G - 6M = -1800000
\n" ); document.write( " * 9G + 6M - 5I = -750000
\n" ); document.write( " * -------------------------
\n" ); document.write( " * 3G - 5I = -2550000\r
\n" ); document.write( "\n" ); document.write( "**Step 5: Solve for G and I**
\n" ); document.write( "* From Equation 1, we can express M as:
\n" ); document.write( " * M = 300000 - G
\n" ); document.write( "* Substitute M in the simplified Equation 2:
\n" ); document.write( " * 3G - 5I = -2550000
\n" ); document.write( " * 3G - 5(150000 - G) = -2550000
\n" ); document.write( " * 8G = 1200000
\n" ); document.write( " * G = 150000
\n" ); document.write( "* Substitute G in M = 300000 - G:
\n" ); document.write( " * M = 300000 - 150000 = 150000
\n" ); document.write( "* Substitute G in I + S = 150000:
\n" ); document.write( " * I + S = 150000
\n" ); document.write( " * I + (150000 - I) = 150000
\n" ); document.write( " * S = 0\r
\n" ); document.write( "\n" ); document.write( "Therefore, the investments are:
\n" ); document.write( "* Gading Mutual Deposit: RM150,000
\n" ); document.write( "* Maju Makmur Bar Gold: RM150,000
\n" ); document.write( "* Indah Certificate Deposit: RM150,000
\n" ); document.write( "* Selamat Maju Bar Gold: RM0
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