# exponential equation

• Nov 4th 2008, 06:50 PM
seanybeaver
exponential equation
hey can someone run me through the steps to solve:

2^2x - 2^(x+3) + 2^4 = 0

thanks much appreciated
• Nov 4th 2008, 09:27 PM
mr fantastic
Quote:

Originally Posted by seanybeaver
hey can someone run me through the steps to solve:

2^2x - 2^(x+3) + 2^4 = 0

thanks much appreciated

$\Rightarrow 2^{2x} - 8 (2^x) + 16 = 0$.

Substitute $w = 2^x$:

$w^2 - 8w + 16 = 0$.

Solve for w. Then solve $2^x = w$ for x.
• Nov 5th 2008, 01:13 AM
seanybeaver
thanks a lot :D