Question 464911
x = 1
----------
The hard way:
{{{2^(2x) + 2^(x+2) - 12 = 0}}}
{{{2^x*(2^x + 4) - 12 = 0}}}
{{{2^2x + 4*2^x - 12 = 0}}}
Sub y for 2^2
{{{y^2 + 4y - 12 = 0}}}
(y+6)*(y-2) = 0
y = 2^x = -6, 2
Ignore the -6 
2^x = 2
x = 1