Evaluate :
log3 8 ÷ log9 16
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Simplifying the expression,
⇒log3 8÷log9 16⇒log 8log 3÷log 16log 9⇒log 8log 3×log 9log 16⇒log 23log 3×log 32log 24⇒3 log 2log 3×2 log 34 log 2⇒6 log 2.log 34 log 2.log 3⇒64⇒32⇒112.\Rightarrow \text{log}3 \space 8 ÷ \text{log}9 \space 16 \\[1em] \Rightarrow \dfrac{\text{log 8}}{\text{log 3}} ÷ \dfrac{\text{log 16}}{\text{log 9}} \\[1em] \Rightarrow \dfrac{\text{log 8}}{\text{log 3}} \times \dfrac{\text{log 9}}{\text{log 16}} \\[1em] \Rightarrow \dfrac{\text{log 2}^3}{\text{log 3}} \times \dfrac{\text{log 3}^2}{\text{log 2}^4} \\[1em] \Rightarrow \dfrac{\text{3 log 2}}{\text{log 3}} \times \dfrac{\text{2 log 3}}{\text{4 log 2}} \\[1em] \Rightarrow \dfrac{\text{6 log 2.log 3}}{\text{4 log 2.log 3}} \\[1em] \Rightarrow \dfrac{6}{4} \\[1em] \Rightarrow \dfrac{3}{2} \\[1em] \Rightarrow 1\dfrac{1}{2}.⇒log3 8÷log9 16⇒log 3log 8÷log 9log 16⇒log 3log 8×log 16log 9⇒log 3log 23×log 24log 32⇒log 33 log 2×4 log 22 log 3⇒4 log 2.log 36 log 2.log 3⇒46⇒23⇒121.
Hence, log3 8 ÷ log9 16 = 1121\dfrac{1}{2}121.
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Solve for x, logx 155=2−logx 3515\sqrt{5} = 2 - \text{log}_x \space 3\sqrt{5}155=2−logx 35
logb a × logc b × loga c
log5 8log 25 16×log 100 10\dfrac{\text{log}5 \space 8}{\text{log }{25} \space 16 \times \text{log }_{100} \space 10}log 25 16×log 100 10log5 8
Show that :
loga m ÷ logab m = 1 + loga b