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2009-12-08T19:36:38+01:00
A) 7|x-4|=2
Ix-4I = -5
x-4 = -5 lub x-4 = 5
x=-1 lub x=9

b) |x|+|x-2|=4

1⁰ = x-x+2 = 4
2=4

2⁰ = x+x-2=4
2x=6
x=3
2009-12-08T19:38:51+01:00
A) 7|x-4|=28
|x-4|=4
x-4=4 ∨ x-4=-4
x=8 ∨x=0

b) |x|+|x-2|=4

1⁰x<0
-x-x+2=4
-2x=2
x=-1 ∈ x<0

2⁰0≤x<2
x-x+2=4
2=4 nieprawda

3⁰x≥2
x+x-2=4
2x=6
x=3 ∈ x≥2
2009-12-08T19:40:49+01:00
A) 7|x-4|=28
28/7=4
x= 8

spr. 7|8-4|= 7*4= 28


b) |x|+|x-2|=4
x²= 4+2=6
x=3

spr. |3|+|3-2|= 3+1 = 4