Răspuns :
1. a. 8 • x = 72
x = 72 : 8
x = 9
e. x : 12 = 15
x = 15 • 12
x = 180
2. a. 4x + 15 = 47
4x = 47 - 15
4x = 32
x = 32 : 4
x = 8
e. 3x - 21 = 45
3x = 45 + 21
3x = 66
x = 66 : 3
x = 22
3. a. 3 - (x + 7) = 129
3 - x - 7 = 129
3 - x = 129 + 7
3 - x = 136
- x = 136 - 3
- x = 133
x = - 133
d. 15 - (18 - x) = 180
15 - 18 + x = 180
x = 180 - 15 + 18
x = 183
g. (x - 4) : 15 = 16
x - 4 = 15 • 16
x - 4 = 240
x = 240 + 4
x = 244
x = 72 : 8
x = 9
e. x : 12 = 15
x = 15 • 12
x = 180
2. a. 4x + 15 = 47
4x = 47 - 15
4x = 32
x = 32 : 4
x = 8
e. 3x - 21 = 45
3x = 45 + 21
3x = 66
x = 66 : 3
x = 22
3. a. 3 - (x + 7) = 129
3 - x - 7 = 129
3 - x = 129 + 7
3 - x = 136
- x = 136 - 3
- x = 133
x = - 133
d. 15 - (18 - x) = 180
15 - 18 + x = 180
x = 180 - 15 + 18
x = 183
g. (x - 4) : 15 = 16
x - 4 = 15 • 16
x - 4 = 240
x = 240 + 4
x = 244
Răspuns:
8x=72
x=72:8=9
x:12=5
x=5x12=60
4x+15=47
4x=47-15
4x=32
x=8
3x-21=45
3x=45+21
3x=66
x=22
3-x-7=129
-x-4=129
-x=129+4
-x=125
x=-125
15-18+x=180
-3+x=180
x=180+3
x=183
x-4=16x15
x-4=240
x=240+4
x=244
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