为什么log9 (9/2)=log3(81/4)

(log3 4+log3 8)(log2 3+log2 9)+(log3 根号2)(log9 7)/(log1/3 7) [log2(3)+log4(9)][log3(4)+log9(2)]等于 计算：（log4 9+log8 3)(log3 2+log9 2)-log1/3 4√81 (log2(3)+log8(9))x(log3(4)+log9(8)+log3(2)) (log2 3+log8 9)(log3 4+log9 8+log3 2)的运算过程 log9(9a+b)=log3√ （ab),求4a+b 的最小值, 求值:(log4^ 3+log8 ^9)*(log3^ 2+log9 ^16) (log3^2 + log9^4)×(log4^3 + log8^3) log 243÷log9 =log3^5÷log3^2 =log3^5-log3^2 然后怎么写 4log9为底 2的对数-log3为底 32/9的对数+log3为底 8的对数-5的2倍log以5为底3的对数 =多少? 计算题：（log2的次方+log8 9的立方）（log3 4的立方+log9 8的立方+log3 2的立方) log3 5-log3 15+1/2log9 27 的值