Question

Нужна помощь (9^2x)-2*(9^x)-3=0

Answer 1

( 9 ^ 2х ) - 2 * ( 9 ^ Х ) - 3 = 0
9 ^ Х = А ; А > 0
а^2 - 2а - 3 = 0
D = 4 + 12 = 16 ; V D = 4
A1 = ( 2 + 4 ) : 2 = 3
A2 = ( 2 - 4 ) : 2 = - 1 ( < 0 )
9 ^ X = 3
3 ^ 2x = 3
2x = 1
X = 0,5