Jika ³log5=b , maka ¹⁵log81=4/1+b

<p><strong>Pembahasan</strong></p><p>³log 5 = b</p><p>maka buktikan ⁠⁠⁠⁠⁠⁠⁠¹⁵log 81 = 4/(1 + b)</p><p>&nbsp;</p><p>¹⁵log 81 = log 3⁴/log (3×5)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 4 log 3/(log 3 + log 5)</p><p>penyebut dan pembilang dibagi log 3/log3</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 4 (log 3/log 3)/( log3/log3 + log 5/log3)&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 4/(1 + (log 5/log 3))</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 4/(1 + ³log 5)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 4/(1 + b)&nbsp;</p><p>&nbsp;</p><p><strong>Terbukti</strong></p><p>&nbsp;</p>