Question

Help please
4ˣ+2ˣ⁺²=12

Answer 1

( 4 ^ x ) + 2 ^ ( x + 2 ) = 12 
2 ^ x = a 
a² + 4a - 12 = 0 
D = 16 + 48 = 64 = 8²
a1 = ( - 4 + 8 ) : 2 = 2 
a2 = ( - 4 - 8 ) : 2 = - 6 ( < 0 ) 
2 ^ x = 2 
x = 1