tolong segera dijawab, besok dikumpulinn

<p>3x-4y+2z = 21 ... (1)</p><p>2x+4y-7z = -16 ... (2)</p><p>-4x-2y+5z = 2 ... (3)</p><p>&nbsp;</p><p>eliminasi (1) dan (2)</p><p>3x-4y+2z = 21&nbsp;</p><p>2x+4y-7z = -16 (ditambah untuk menghilangkan y)</p><p>5x-5z = 5 ... (4)</p><p>&nbsp;</p><p>eliminasi (2) dan (3)</p><p>2x+4y-7z = -16</p><p>-4x-2y+5z = 2 (dikali 2, lalu ditambah agar menghilangkan y)</p><p>&nbsp;</p><p>2x+4y-7z = -16</p><p>-8x-4y+10z = 4</p><p>&nbsp;</p><p>-6x+3z = -12 (5)</p><p>&nbsp;</p><p>eliminasi (4) dan (5)</p><p>&nbsp;</p><p>5x-5z = 5 (kali 6)</p><p>-6x+3z = -12 (kali 5)</p><p>&nbsp;</p><p>30x-30z = 30</p><p>-30x+15z = -60 (ditambah)</p><p>&nbsp;</p><p>-15z = -30</p><p>z = 2</p><p>&nbsp;</p><p>30x-30(2) = 30</p><p>30x -60 = 30</p><p>30x = 90</p><p>x = 3</p><p>&nbsp;</p><p>substitusi x dan z ke persamaan (1)</p><p>3x-4y+2z = 21 ... (1)</p><p>&nbsp;</p><p>3(3)-4y+2(2) = 21</p><p>9-4y+4 = 21</p><p>13-4y = 21</p><p>13-21 = 4y</p><p>-8 = 4y&nbsp;</p><p>y = -2</p><p>&nbsp;</p><p>Semoga membantu!</p>