Gess aku gak dong ini gimana sih?

<p>&nbsp;</p><p>Hai.</p><p><strong>No.7</strong> &nbsp;145x76=76x(96+a) &nbsp;</p><p>Karena ruas kanan dan kiri sama sama perkalian, maka masing-masing dibagi dengan 76</p><p>(145x76)/76=(76/76)x(96+a)</p><p>145 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; =96+a</p><p>145-96 &nbsp; &nbsp; &nbsp; &nbsp; =a</p><p>49 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;=a</p><p>&nbsp;</p><p><strong>No. 8</strong> &nbsp; &nbsp;a=-3, b=5 dan c=-7 maka 3a+2b-c-(a-b+c)</p><p>jawab:</p><p>3a+2b-c-(a-b+c)</p><p>=3a+2b-c-a+b-c. &nbsp;<strong>gabung sesuai variabel&nbsp;</strong></p><p>=3a-a+2b+b-c-c</p><p>=2a+3b-2c</p><p>=2(-3)+3(5)-2(-7) <strong>masukkan nilai a,b,c nya</strong></p><p>=-6+15+14</p><p>=23</p>