15-3(x+2)=0
3(x+2)=15+0
3(x+2)=15
x+2=15:3
x+2=5
x=5-2
x=3
Bài 2:
a; 34.1.22 - 22.34
= 34.22 - 22.34
= 34.(22 - 22)
= 34.0
= 0
b; 43.18 + 62.18
= 64.18 + 62.18
= 18.(64 + 62)
= 18.126
= 2268
c; 25.46 + 50.27
= 25.46+ 25.(2.27)
= 25.46 + 25.54
= 25.(46 + 54)
= 25.100
= 2500