Question

rezolvati in multimea numerelor naturale urmatoarele inecuatii.. Va rog repede .....
a) 3x+7≤ x+13
b) 2(x+1)-3(x-1) > 3(x+6)-5(2+x).

Answer 1

a)2x≤6 
  x≤3 => x apartine {0,1,2,3}
b)2x+2-3x+3>3x+18-10-5x
-x+5>-2x+8
x>3 => x apartine {4,5,6....}

Answer 2

       
$a) \\ 3x+7 \leq x+13 \\ 3x-x \leq 13-7 \\ 2x \leq 6 \\ x \leq \frac{6}{2} \\ x \leq 3 \\ x\; \epsilon \;\{0;1; 2;3 \}$


$b) \\ 2(x+1)-3(x-1)\ \textgreater \ 3(x+6)-5(2+x) \\ 2x+2-3x+3\ \textgreater \ 3x+18-10-5x \\ -x+5\ \textgreater \ -2x+8 \\ -x+2x\ \textgreater \ 8-5 \\ x\ \textgreater \ 3 \\ x\;\epsilon\;\{4;5;6;7......... \}$