[tex] x^{2} \leq 7-4 \sqrt{15-4 \sqrt{11} } [/tex]
[tex] \sqrt{15-4 \sqrt{11} }= \sqrt{( \sqrt{11}-2)^{2} } = | \sqrt{11}-2 | = \sqrt{11}-2[/tex]
[tex] x^{2} \leq 7-4*( \sqrt{11}-2) \ \textless \ =\ \textgreater \ x^{2} \leq 7-4 \sqrt{11}+8 \ \textless \ =\ \textgreater \ x^{2} \leq 15-4 \sqrt{11} [/tex]
[tex] x^{2} \leq 15-4 \sqrt{11} \ \textless \ =\ \textgreater \ x^{2} \leq ( \sqrt{11}-2)^{2} \ \textless \ =\ \textgreater \ x \leq \sqrt{11}-2 [/tex]
√11 ≈ 3,3 → o sa-l luam 3 ,deoarece x ∈ Z
[tex]x \leq 3-2 \ \textless \ =\ \textgreater \ x \leq 1
[/tex]
x ∈ Z
⇒ x ∈ (-∞ ;1]
