a, 3.(7+x)=88-64
3.(7+x)=24
7+x=24:3
7+x=8
x=1
b,7x=114-44
7x=70
x=70:7
x=10
c,31x-41=114
31x=114+41
31x=155
x=5
k như đã nói nha 3 cái nha
3.(7+x)=88-64 7x=114-44. 31x-41=57.2
3.(7+x)=24 7x=70 31x-41=114
7+x=24:3 x=70:7 31x =114+41
7+x=8 x=10 31x =155
x=8-7 x =155:31
x = 5
x=1