c) 256 : 4x = 42a) 2x : 4 = 32
=2x =32.4
=2x =128
=2x =27
=x =7
b) 3x : 32 = 243
=3x =243.27
=3x =6561
=3x =38
=x =8
c) 256 : 4x = 42
= 256 : 4x = 16
= 4x = 42
= x =2
d) 5x : 25 = 25
=5x =25.25
=5x =625
=5x =54
=x =4
e) 5x+1: 5 = 54
=5x+1 : 5 =625
=5x+1 =625.5
=5x+1 =3125
=5x+1 =55
=x =5
(bị lú đề,còn câu f thì chịu)