q=log27(32)=5lg2/(3lg3)=5(1-lg5)/(3lg3)
所以lg3=5(1-lg5)/(3q)
p=log9(25)=2lg5/(2lg3)
所以lg3=2lg5/(2p)
所以5(1-lg5)/(3q)=2lg5/(2p)
lg5=5p/(3q+5p)