Find the range of mmm for which the inequality x2−mx+1x2+x+1<3\frac{x^2 - mx + 1}{x^2 + x + 1} < 3x2+x+1x2−mx+1<3 holds for all real xxx.
m<2m < 2m<2
−5<m<1-5 < m < 1−5<m<1
m>5m > 5m>5
−2<m<4-2 < m < 4−2<m<4