ini bgmn caranya?

<p>Jawaban&nbsp;</p><p>&nbsp;Ukuran persegi tsb adalah&nbsp;</p><p><strong>panjang = 9 cm</strong></p><p><strong>lebar = 9 cm</strong></p><p>&nbsp;</p><p>&nbsp;</p><p><strong>Pembahasan&nbsp;</strong></p><p>Luas persegi = p × l</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = (x+5)(13-x)</p><p>&nbsp;</p><p>L = -x² + 8x +65</p><p>&nbsp;</p><p>Fungsi turunan untuk mencari nilai max.&nbsp;</p><p>L' = -2x + 8 = 0</p><p>&lt;=&gt; 2x = 8</p><p>&lt;=&gt; x = 4</p><p>&nbsp;</p><p>Panjang: 4 + 5 = 9 cm</p><p>Lebar: 13 - 4 = 9 cm</p>