log(2x)+log(3y)-log(2z) 怎么化简? log3(x^2-2x-6)=2 log(3x+6)=1+log(x)求解.

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log(2x)+log(3y)-log(2z) 怎么化简? log3(x^2-2x-6)=2 log(3x+6)=1+log(x)求解.

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