Question

[x-5] +2[x+11]=20
Aflati x. In acest exercitiu, Parantezele patrate inseamna parte intreaga a numarului respectiv. x apartine multimii nr reale

Answer 1

[x-5]+2[x-5+16]=20

[x-5]+2([x-5]+16)=20

[x-5]+2[x-5]+32=20

3[x-5]=20-32=-12

[x-5]=-4
-4≤x-5<-3 adaugam 5 la gfiecare membru al dublei inegalitati
1≤x<2
adica
x∈[1;2) care verifica