Răspuns:
Explicație pas cu pas:
1.
2 x + 5 = x + 6
2 x - x = 6 - 5
x = 1
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2.
3 x - 1 = x + 9
3 x - x = 9 + 1
2 x = 10
x = 10 : 2
x = 5
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3.
2 x - 5 = - x + 7
2 x + x = 7 + 5
3 x = 12
x = 12 : 3 => x = 4
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4.
- x + 7 = x + 21
- x - x = 21 - 7
- 2 x = 14
x = 14 : ( - 2) => x = - 7
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5.
1 + 9 x = - 89 - x
9 x + x = - 89 - 1
10 x = - 90
x = ( - 90 ) : 10 => x = - 9
_________________________
6.
2(x-3) = - 6
2 x - 6 = - 6
2 x = 6 + 6
2 x = 0 => x = 0
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7.
- 4(x-2) = 12
- 4 x + 8 = 12
- 4 x = 12 - 8
- 4 x = 4
x = 4 : ( - 4) => x = - 1
_____________________
8.
- 7 ( x - 3 ) = - 14
- 7 x + 21 = - 14
- 7 x = - 14 - 21
- 7 x = - 35
x = ( - 35) : ( - 7) => x = 5
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9.
- 5 ( x - 3 ) + 7 = 2
- 5 x + 15 + 7 = 2
- 5 x + 22 = 2
- 5 x = 2 - 22
- 5 x = - 20
x = ( - 20) : ( - 5) => x = 4
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10.
- 6 ( x + 7 ) + 3 x = - 42
- 6 x - 42 + 3 x = - 42
- 3 x = - 42 + 42
- 3 x = 0 => x = 0
