Bantu jawab

<p><strong>Jawaban yang tepat :</strong></p><p>a = 1</p><p>b = -1</p><p>c = 2</p><p>&nbsp;</p><p><strong>Pembahasan :</strong></p><p>9a + 3b + c = 8 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(1)</p><p>4a + 2b + c = 4 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(2)</p><p>a + b + c = 2 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (3)</p><p>&nbsp;</p><p>Eliminasi c dari persamaan (1) dan (2)</p><p>9a + 3b + c = 8</p><p><u>4a + 2b + c = 4&nbsp;</u> _</p><p>5a + b = 4 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(4)</p><p>&nbsp;</p><p>Eliminasi c persamaan dari persamaan (2) dan (3)&nbsp;</p><p>4a + 2b + c = 4&nbsp;</p><p><u>a + &nbsp; &nbsp;b + &nbsp;c &nbsp;= 2&nbsp;</u> _</p><p>3a + b &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 2 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (5)</p><p>&nbsp;</p><p>Eliminasi b dari persamaan (4) dan (5)</p><p>5a + b = 4 &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</p><p><u>3a + b = 2&nbsp;</u><i> _</i></p><p><i>2a = 2</i></p><p><i>a = 1</i></p><p>&nbsp;</p><p>Substitusikan a = 1 ke persamaan (4)</p><p>5a + b = 4 &nbsp; &nbsp; &nbsp;</p><p>5(1) + b = 4 &nbsp; &nbsp; &nbsp;</p><p>b = 4 - 5</p><p>b = -1</p><p>&nbsp;</p><p>Substitusikan a = 1 dan b -1 ke persamaan (3)</p><p>a + b + c = 2</p><p>1 + (-1) + c = 2</p><p>c = 2</p><p>&nbsp;</p><p>&nbsp;</p>