Odpowiedź:
1.
10x - 5 = 4x + 1
10x - 4x = 1 + 5
6x = 6 /:6
x = 1
15x - 5x = 20
10x = 20 /:10
x = 2
2.
a) x - 3 = 7 ; 9
9 - 3 = 7
6 ≠ 7 nie
b) 4 (x + 2) = 8 ; 0
4x + 8 = 8
4 * 0 + 8 = 8
0 + 8 = 8
8 = 8 tak
c) 3x + 2 = 5 ; 1
3 * 1 + 2 = 5
3 + 2 = 5
5 + 5 tak
d) 5 - 2X = 1 ; 3
5 - 2 * 3 = 1
5 - 6 = 1
- 1 ≠ 1 nie
3.
a) 2x = 10 / : 2
x = 5
b) 2x - 3 = 5
2x = 5 + 3
2x = 8 /:2
x = 4
c) 9 + 3x = - 6
3x = - 6 - 9
3x = - 15 /: 3
x = - 5
d) 2x - 1 = 4x + 2
2x - 4x = 2 + 1
- 2x = 3 / : (- 2)
x = - 3/2
x = - 1 1/2
e) 3 - x = 2x + 6
- x - 2x = 6 - 3
- 3x = 3 / :(- 3)
x = - 1
f) x + 8 = - 8 + 5x
x - 5x = - 8 - 8
- 4x = - 16 /: (- 4)
g) 4 + 2x = 15 - x
2x + x = 15 - 4
3x = 11 / : 3
x = 11/3
x = 3 2/3
h) 2 (3x - 5) = 8
6x - 10 = 8
6x = 8 + 10
6x = 18 / : 6
x = 3
Szczegółowe wyjaśnienie:
