16^(㏒₂6) -5^(-㏒₅ 1/7) =2^(4㏒₂6) - 5(㏒₅ 7)=6⁴-7=1296-7=1289
㏒₀,₅0,64+㏒₀,₅10=1/2㏒₀,₅0,64 +㏒₀,₅10 =㏒₀,₅(0,64)¹/₂ * 10 =㏒₀,₅0,8*10=㏒₀,₅8
㏒₀,₅0,125 * ㏒₇64 ㏒₀,₅0,5³ * ㏒₇2⁵ 3*1*5*㏒₇2
-------------------------- = ---------------------= -------------------- = 15
㏒₇2 ㏒₇ 2 ㏒₇2