Dinda membeli jeruk sebanyak 4 kg dan apel sebanyak 2kg dengan harga Rp 96.000. Dede membeli jeruk sebanyak 2kg dan apel sebanyak 3kg dengan harga Rp 72.000, berapakah harga kg jeruk dan 1 kg apel?

<p>Misalkan x = jeruk dan y = apel maka persamaan matematikanya :</p><p>4x + 2y = 96.000 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (1)</p><p>2x + 3y = 72.000 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(2)</p><p>&nbsp;</p><p><strong>Eliminasi y untuk mencari nilai x</strong></p><p>4x + 2y = 96.000 --&gt; (dikali 3) --&gt; 12x + 6y = 288.000 &nbsp;&nbsp;</p><p>2x + 3y = 72.000 --&gt; (dikali 2) --&gt; &nbsp;&nbsp;<u>4x + 6y = 144.000 &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; &nbsp; &nbsp;8x &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 144.000</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;x = 144.000 : 8</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; &nbsp; = 18.000</p><p>Harga 1 kg jeruk adalah Rp. 18.000;</p><p>&nbsp;</p><p><strong>Substitusikan x = 18.000 ke persamaan (2)</strong></p><p>2x + 3y = 72.000</p><p>2(18.000) + 3y = 72.000</p><p>36.000 + 3y = 72.000</p><p>3y = 72.000 - 36.000</p><p>3y = 36.000</p><p>y = 36.000 : 3</p><p>&nbsp; &nbsp; = 12.000</p><p>Jadi harga 1 kg apel adalah Rp. 12.000;</p><p>&nbsp;</p><p>Harga 1 kg Jeruk dan 1 kg apel = x + y</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; = Rp. 18.000 + Rp. 12.000</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; = <strong>Rp. 30.000</strong></p>