| x 2 − 6 x + 7 | ≥ 9 {\displaystyle \ |x^{2}-6x+7|\geq 9} x 2 − 6 x + 7 ≥ 2 {\displaystyle \ x^{2}-6x+7\geq 2} או x 2 − 6 x + 7 ≤ − 2 {\displaystyle \ x^{2}-6x+7\leq -2}
x 2 − 6 x + 7 ≤ − 2 x 2 − 6 x + 7 ≤ − 2 x 2 − 6 x + 9 ≤ 0 ( x − 3 ) 2 ≤ ( x − 3 ) 2 = 0 ↓ x = 3 {\displaystyle {\begin{aligned}&x^{2}-6x+7\leq -2\\&x^{2}-6x+7\leq -2\\&x^{2}-6x+9\leq 0\\&(x-3)^{2}\leq \\&(x-3)^{2}=0\\&\downarrow \\&x=3\\\end{aligned}}}
x ≥ 5 ; x ≤ 1 ; x = 3 {\displaystyle {\begin{aligned}&x\geq 5;x\leq 1;x=3\end{aligned}}}
