# Math Help - Log question with negative exponent

1. ## Log question with negative exponent

4^x + 6(4^-x) = 5

Can anyone please help me, I have been trying to solve this for hours

2. Originally Posted by toony
4^x + 6(4^-x) = 5
$4^x+6\cdot 4^{-x}=5$ is same as $4^{2x}-5\cdot 4^x +6 = 0$ (we multiply by $4^x$).

Can you solve $z^2-5z+6=0?$
If so let each of those $z's$ equal $4^x$ and solve.

3. Wow thanks. didnt notice that !