1. Rezolvaţi în R:
a) 2x + 5 = 7 + x
d) 5x+5 = 2x – 7
g) 5x – 1 = 8x + 11
b) 7x+3 = 2x + 23
e) 7 – 2x = 5x – 14
h) 3x – 1 = 5x +9
c) 4x+1 = x + 16
f) 9x – 4 = 5x + 8
i) 6x – 5 = 3x + 7
Răspunsuri la întrebare
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Răspuns:
a) x=2; d) x=-4; g) x=-4; b) x=4; e) x=3; h) x=-5; c) x=5; f) x=3; i) x=4;
Explicație pas cu pas:
a) 2x + 5 = 7 + x
2x - x + 5 = 7
x = 7 - 5
x = 2
d) 5x + 5 = 2x – 7
5x - 2x + 5 = - 7
3x = - 7- 5
3x = - 12
x = - 12 : 3
x = - 4
g) 5x – 1 = 8x + 11
5x - 8x - 1 = 11
- 3x = 11 + 1
- 3x = 12
x = 12 : ( - 3 )
x = - 4
b) 7x + 3 = 2x + 23
7x - 2x + 3 = 23
5x = 23 - 3
5x = 20
x = 20 : 5
x = 4
e) 7 – 2x = 5x – 14
- 2x - 5x = - 14 - 7
- 7x = - 21
x = - 21 : ( - 7 )
x = 3
h) 3x – 1 = 5x + 9
3x - 5x - 1 = 9
- 2x = 9 + 1
- 2x = 10
x = 10 : ( - 2 )
x = - 5
c) 4x + 1 = x + 16
4x - x + 1 = 16
3x = 16 - 1
3x = 15
x = 15 : 3
x = 5
f) 9x – 4 = 5x + 8
9x - 5x - 4 = 8
4x = 8 + 4
4x = 12
x = 12 : 4
x = 3
i) 6x – 5 = 3x + 7
6x - 3x - 5 = 7
3x = 7 + 5
3x = 12
x = 12 : 3
x = 4