Question

Calculati multimea:b=x€N\10x-1≤59

Answer 1

10x-1< sau egal 59=>10x<sau egal 59+1=>10x<sau egal 60=>x<sau egal 60/10=>x<sau egal 6 =>b={0;1;2;3;4;5;6}

Answer 2

10x-1 ≤ 59⇒10x≤ 59 +1⇒10x≤ 60⇒x≤ 60/10⇒x≤ 6⇒b.≈ (0,1,2,3,4,5,6)