a ) 5 ^ x = 125
=> 5 ^ x = 5 ^ 3
=> x = 3
vậy x = 3
b ) 3 ^ ( 2 * x ) = 81
=> 3 ^ ( 2 * x ) = 3 ^ 4
=> 2 * x = 4
=> x = 4 / 2
=> x = 2
vậy x = 2
tick mk nha TRẦN BÍCH LỆ
a).5x = 125 ( 5x = 53 => x= 3
b) 32x = 81 => 32x = 34 => 2x = 4 => x = 2
tich nha ha nha
a)
=> 5x = 53
=> x = 3
b)
=> 32x = 34
=> x = 4 : 2 = 2