Lista 2 Zadanie 13

a)
9x - [4x - (4+x)] = 4x - 2
9x - (4x - 4 - x) = 4x - 2
9x - 4x + 4 + x = 4x -2
6x + 4 = 4x - 2 | -4
2x = -6 | : 2
x = -3

b)
13 + [5u - (7u +9) + 12u] - 15 = 9
13 + 5u - 7u - 9 + 12 - 15 = 9
1 - 2u= 9 | -1
-2u = 8 | * (-1)
2u = -8 | : 2
u = -4

c)
13- 4w - [ 47 - (41 - 7w)] = 3w
13 - 4w - [47 - 41 + 7w) = 3w
13 - 4w - 47 + 41 - 7w = 3w
7 - 11w = 3w | +11w
7= 14w | :14
7/14 =w
1/2=w

d)
1,2 = 5,7 - [7,6x - (1,2x - 6,9)]
1,2 = 5,7 - ( 7,6 - 1,2x +6,9)
1,2 = 5,7 - 7,6x + 1,2x -6,9
1,2 = -1,2 - 6,4x | + 12
2,4 = -6,4x | * (-10)
-2,4 = 64x | : 64
-24/64 = x
-1/8 = x

Jeśli są jakieś błędy, to piszcie w komentarzach :)
Pozdrawiam :)