Let Y=4^x
Y^2 - 17Y + 16 = 0
(Y-16) (Y-1) = 0
Y = 16 OR Y = 1
4^x = 16 OR 4^x = 1
You should be able to work it out easily at this point but if not:
log[SIZE="1"]4[/SIZE] 16 = x = 2
OR
log[SIZE="1"]4[/SIZE] 1 = x = 1 Edit: correction. log[SIZE="1"]4[/SIZE] 1 = 0
x = 2 OR 0
(unless of course you're working in graphical form and trying to find points of intersection in which case x = 2 AND 0)
Now gimme a hard one!