12≤x≤−612 \leq x \leq-612≤x≤−6
1.6≤x≤−8.81.6 \leq x \leq-8.81.6≤x≤−8.8
−3.6≤x≤−1.8-3.6 \leq x \leq-1.8−3.6≤x≤−1.8
1.8≤x≤−3.61.8 \leq x \leq-3.61.8≤x≤−3.6