Tolong kak

<p>jawaban e.4<br>2x+3y-z=9 .. (pers.1)</p><p>4x-5y+2z=1 .. (pers.2)</p><p>x+y+z=9 .. =&gt; ubah jadi z=9-x-y .. (pers.3), masukin ke (pers.1)</p><p>2x+3y-(9-x-y)=9</p><p>2x+3y-9+x+y=9</p><p>3x+4y-9=9</p><p>3x+4y=18 .. (pers.4)</p><p>z=9-x-y .. (pers.3) masukin ke (pers.2)</p><p>4x-5y+2(9-x-y)=1<br>4x-5y+18-2x-2y=1</p><p>2x-7y=-17 .. (pers.5)</p><p>dari (pers.4) dan (pers.5) eliminasi y</p><p>3x+4y=18 _kali 7</p><p>2x-7y=-17 _kali 4</p><p>21x+28y=126</p><p>8x-28y=-68</p><p>______________+</p><p>29x=58</p><p>&nbsp; &nbsp; &nbsp;<strong>x=2</strong></p><p>masukin x=2 ke 3x+4y=18</p><p>3(2)+4y=18<br>4y=18-6</p><p>4y=12</p><p>&nbsp;<strong> y=3</strong></p><p><strong>masukin x dan y ke z=9-x-y</strong></p><p>z=9-2-3</p><p>z=4</p><p>maaf kalau salah<br>&nbsp;</p>