log(2x)+log(3y)-log(2z) 怎么化简? log3(x^2-2x-6)=2 log(3x+6)=1+log(x)求解.
问题描述：
log(2x)+log(3y)-log(2z) 怎么化简? log3(x^2-2x-6)=2 log(3x+6)=1+log(x)求解.
答
log(2x)+log(3y)-log(2z)=log(12xyz)
log3(x^2-2x-6)=2=log3(9) x^2-2x-6=9 x=-3 x=5 x=5使得x^2-2x-6