Question

Rezolvati ecuatia |x-1|+|1-x|=4

Answer 1

|x-1|+|1-x|=4
|x-1|+|-(x-1)|=4
|x-1|+|x-1|=4
2|x-1|=4
|x-1|=2

x1-1=2
x2-1=-2

x1=3
x2=-1

S={-1;3}.

Answer 2

x-1+|1-x|=4 sau -x+1+|1-x|=4 ⇔ x-1+1-x=4 sau x-1-1+x=4 sau x+1+1-x=4 sau x+1-1+x=4 ⇔ 0=4 sau 2x-2=4 sau 2=4 sau 2x=4 ⇔x=3 sau 2 ⇔ x∈{2,3}