20 - 2.(x+4) = 4
2.(x+4) = 20 - 4
2.(x+4) = 16
x+4 = 16 : 2
x+4 = 8
x = 8 - 4
x = 4
2(x-1):3=43 + 23
2(x-1):3= 64 + 8
2(x-1):3= 72
2(x-1) = 72 x 3
2(x-1) = 216
x - 1 = 216 : 2
x - 1 = 108
x = 108 + 1
x = 109
Hok tốt !
20-2(x+4)=4
2(x+4)=20-4
2(x+4)=16
x+4=16:2
x+4=8
x=8:4
x=2
Vậy x=2
12(x-1):3=43+23
12(x+1):3=64+8
12(x+1):3=72
12(x+1)=72.3
12(x+1)=216
x+1=216:12
x+1=18
x=18-1
x=17
Vậy x=17