m+m/1=3两边平方m²+2×m×m/1+m²/1=3²m²+2+m²/1=9m²+m²/1=7(m-m/1)²=m²-2×m×m/1+m²/1=m²-2+m²/1=7-2=5
分数线反了m+1/m=3(m+1/m)^2=9m^2+1/m^2+2=9m^2+1/m^2-2=5(m-1/m)^2=5
