Tính chất: Nếu +[tex]\frac{a}{b}<\frac{c}{d}thì \frac{a}{b}<\frac{a+c}{b+d}<\frac{c}{d}[/tex]
Áp dụng ta có:[tex]\frac{2018}{2019}>\frac{2018^{2018}}{2019^{2019}}\Rightarrow \frac{2018}{2019}>\frac{2018^{2018}+2018}{2019^{2019}+2019}>\frac{2018^{2018}}{2019^{2019}}[/tex] [tex]\Rightarrow N>M[/tex]