Question

solve for x. log(x+12)=2log(x)

Answer 1

well you can rewrite them using log laws

\[lof(x +12) = \log(x^2)\]

then raise each side as a power of the base

and you then need to solve

x + 12 = x^2

or x^2 - x - 12 = 0

now solve for x.

hope it helps

Answer 2

that's right now you can factorize it easily

x^2 -x -12 = (x - 4)(x + 3)

x = 4 and -3

Answer 3

reject -3 because we need `x > 0` for the expression `log(x)` to be real

Answer 4

are you sure about x = -3



log (-3 + 12) = log((-3)^2)

I think you have to include x = -3 as a solution

Answer 5

it's always an interesting question...

Answer 6

\(\log(x^2)\) is not necessarily same as \(2\log x\)

Answer 7

that holds only when \(x\) is positive

Answer 8

thanks everyone!