Răspuns :
x² + x ≤ x² - 6x + 9
x ² + x - x² + 6x ≤ 9
x + 6x ≤ 9
7x ≤ 9
x ≤ 9 / 7
x ≤ 1,28
x natural
x ∈ { 0 ,1 }
x ² + x - x² + 6x ≤ 9
x + 6x ≤ 9
7x ≤ 9
x ≤ 9 / 7
x ≤ 1,28
x natural
x ∈ { 0 ,1 }
[tex]\displaystyle x(x+1) \leq (x-3)^2 \\ x^2+x \leq x^2-2 \cdot x \cdot 3+3^2 \\ x^2+x \leq x^2-6x+9 \\ x^2+x-x^2+6x \leq 9 \\ 7x \leq 9 \\ x \leq \frac{9}{7} \\ x \leq 1,285 \\ x \in \{0;1\}[/tex]