明天上午就要 最好今天 (17 18:57:2)①已知log1227=a,求证:log616=4(3-a)                                                         ̄ ̄ ̄                                                         3+a②已知32x=43y=126,求3    2的值                                         ̄+ ̄                                         x     y

问题描述:

明天上午就要 最好今天 (17 18:57:2)
①已知log1227=a,求证:log616=4(3-a)
                                                         ̄ ̄ ̄
                                                         3+a
②已知32x=43y=126,求3    2的值
                                         ̄+ ̄
                                         x     y

log12 27=3log12 3=a
则: 4(3-a)/(3+a)=4(3-3log12 3)/(3+3log12 3)=4(1-log12 3)/(1+log12 3)
=4log12 4/log12 36=4log36 4=4/2 log6 4=log6 16
额~ 第二道 我汗~

1.log12 27=3log12 3=a则:4(3-a)/(3+a)=4(3-3log12 3)/(3+3log12 3)=4(1-log12 3)/(1+log12 3)=4log12 4/log12 36=4log36 4=4/2 log6 4=log6 16 2.32x=43y=126 x=126/32 y=126/433/x+2/y=3*32/126+2*43/126=182/126=...