Răspuns :
3x-21=45
3x=45+21
3x=66
x=22
320-7x=243
7x=320-243
7x=77
x=11
116-4x=80
4x=116-80
4x=36
x=9
5x-23=72
5x=72+23
5x=95
x=19
3x=45+21
3x=66
x=22
320-7x=243
7x=320-243
7x=77
x=11
116-4x=80
4x=116-80
4x=36
x=9
5x-23=72
5x=72+23
5x=95
x=19
a)3x-21=45
3x=66
x=66 :3
x=22
b)320-7x=243
-7x = 243-320
-7x=-77
x=11
c)116-4x=80
-4=80-116
-4x=-36
x=9
d)5x-23=72
5x=72+23
5x=95
x=19
3x=66
x=66 :3
x=22
b)320-7x=243
-7x = 243-320
-7x=-77
x=11
c)116-4x=80
-4=80-116
-4x=-36
x=9
d)5x-23=72
5x=72+23
5x=95
x=19