diketahui sistem persamaan linear 5x+9y=-25 x-4y=24 berapakah nilai dari 7x-12y? TOLONG KA YG BISA

<p>Jawaban yang tepat adalah 88</p><p>&nbsp;</p><p>Pembahasan :</p><p>5x + 9y = -25 &nbsp; &nbsp;(1)</p><p>x - 4y = 24 &nbsp; &nbsp; &nbsp; &nbsp; (2)</p><p>&nbsp;</p><p>Eliminasi variabel x untuk mendapatkan nilai y</p><p>5x + 9y = -25 &nbsp; --&gt; (dikali 1) --&gt; 5x + 9y = -25</p><p>x - &nbsp;4y &nbsp;= &nbsp;24 &nbsp; &nbsp; --&gt; (dikali 5) --&gt; <u>5x - 20y = 120</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; &nbsp; &nbsp; 29y = -145</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; &nbsp; y = -145 : 29</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; &nbsp; y = -5</p><p>&nbsp;</p><p>Substitusikan y = -5 ke persamaan (2) untuk mendapatkan nilai x</p><p>x - 4y = 24 &nbsp;</p><p>x - 4(-5) = 24 &nbsp;</p><p>x + 20 = 24</p><p>x = 24 - 20</p><p>x = 4</p><p>&nbsp;</p><p>Nilai 7x - 12y = 7(4) - 12(-5)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 28 + 60</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 88</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;</p>