若3/log2 19+2/log3 19+1/log5 19=log19 m,求m的值
问题描述:
若3/log2 19+2/log3 19+1/log5 19=log19 m,求m的值
答
3/log2(19)+2/log3(19)+1/log5(19)=log19(m)
3log19(2)+2log19(3)+log19(5)=log19(m)
log19(4)+log19(9)+log19(5)=log19(m)
log19(4×9×5)=log19(m)
m=180