Math
posted by Sabrina on .
Are you allowed to do this
2log(x1) =log(x+1)
2 (x1)=(x+1)
x=3
Please help :)


Some mathteacher published a book some time ago listing all the silly solutions that students had produced.
It actually had it this way
2log(x1) =log(x+1)
(2log(x1))/log = (log(x+1))/log , then the log/log canceled
2(x1) = (x+1)
2x  2 = x+1
x = 3, which by sheer coincidence is the right answer. 
My teacher showed us this one:
64/16
= (6)4/1(6) [cancel the 6]
= 4/1
= 4
gets the right answer, but the wrong way.