x + 4y = 7 2x + 3y = 9 Kerjakan dengan metode a. eliminasi b. subtitusi c. campuran

<p>x + 4y = 7 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (1)<br>2x + 3y = 9 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (2)</p><p>&nbsp;</p><p>a. <strong>Metode Elimiminasi</strong></p><p>&nbsp; &nbsp;&nbsp;<strong> Eliminasi variabel x untuk mendapatkan nilai y</strong></p><p>&nbsp; &nbsp; &nbsp;x + 4y = 7 &nbsp; &nbsp;(dikali 2) ---&gt; 2x + 8y = 14<br>&nbsp; &nbsp; 2x + 3y = 9 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;---&gt; <u>2x + 3y = 9 &nbsp;&nbsp;</u> _</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 5y = 5</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; y = 1</p><p>&nbsp; &nbsp;&nbsp;<strong>Eliminasi Variabel y untuk mendapatkan nilai x</strong></p><p>&nbsp; &nbsp; x + 4y = 7 &nbsp; &nbsp; &nbsp; (dikali 3) --&gt; 3x + 12y = 21<br>&nbsp; &nbsp; 2x + 3y = 9 &nbsp; &nbsp; (dikali 4) --&gt; <u>8x + 12y = 36&nbsp;</u> _</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-5x &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= -15</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; x = 3</p><p>&nbsp; &nbsp; Himpunan Penyelesaian adalah {3,1}</p><p>&nbsp;</p><p>b. <strong>Metode Substitusi</strong></p><p>&nbsp; &nbsp; &nbsp;x + 4y = 7 --&gt; x = 7 - 4y &nbsp; &nbsp; &nbsp; &nbsp;(1)<br>&nbsp; &nbsp; &nbsp;2x + 3y = 9 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(2)</p><p>&nbsp;</p><p>&nbsp; &nbsp;&nbsp;<strong> Substitusikan persamaan (1) Ke persamaan (2)</strong></p><p>&nbsp; &nbsp; &nbsp;2x + 3y = 9</p><p>&nbsp; &nbsp; &nbsp;2(7 - 4y) + 3y = 9</p><p>&nbsp; &nbsp; &nbsp;14 - 8y + 3y = 9</p><p>&nbsp; &nbsp; &nbsp;-5y = 9 - 14</p><p>&nbsp; &nbsp; &nbsp;-5y = -5</p><p>&nbsp; &nbsp; &nbsp; y = 1</p><p>&nbsp; &nbsp; &nbsp;<strong>Substitusikan y = 1 ke persamaan (1)</strong></p><p>&nbsp; &nbsp; &nbsp; x = 7 - 4y</p><p>&nbsp; &nbsp; &nbsp; x = 7 - 4(1)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 7 - 4</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 3</p><p>&nbsp; &nbsp; &nbsp; &nbsp; Himpunan Penyelesaian adalah {3,1}</p><p>&nbsp;</p><p>C. <strong>Metode Campuran&nbsp;</strong></p><p><strong>&nbsp; &nbsp; &nbsp;</strong>x + 4y = 7 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (1)<br>&nbsp; &nbsp; &nbsp;2x + 3y = 9 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (2)</p><p><strong>&nbsp; &nbsp; &nbsp; Eliminasi variabel x untuk mendapatkan nilai y</strong></p><p>&nbsp; &nbsp; &nbsp; x + 4y = 7 &nbsp; &nbsp;(dikali 2) ---&gt; 2x + 8y = 14<br>&nbsp; &nbsp; &nbsp;2x + 3y = 9 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ---&gt; <u>2x + 3y = 9 &nbsp;&nbsp;</u> _</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 5y = 5</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; y = 1</p><p>&nbsp; &nbsp; &nbsp;&nbsp;<strong>Substitusikan y = 1 ke persamaan (1)</strong></p><p>&nbsp; &nbsp; &nbsp; &nbsp;<strong> </strong>x + 4y = 7&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp;x + 4(1) = 7&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp;x = 7 - 4</p><p>&nbsp; &nbsp; &nbsp; &nbsp;x = 3</p><p>&nbsp; &nbsp; &nbsp; &nbsp;Himpunan Penyelesaian adalah {3,1}</p>