Xin hay nhất nhé tus ^_^
$\frac{3}{2.4}$ `+` $\frac{3}{4.6}$ `+` $\frac{3}{6.8}$ `+...+` $\frac{3}{98.100}$
`=` $\frac{3}{2}$`(`$\frac{2}{2.4}$ `+` $\frac{2}{4.6}$ `+` $\frac{2}{6.8}$ `+...+` $\frac{2}{98.100}$`)`
`=` $\frac{3}{2}$`(`$\frac{1}{2}$ `-` $\frac{1}{4}$ `+` $\frac{1}{4}$ `-` $\frac{1}{6}$ `+...+` $\frac{1}{98}$ `-` $\frac{1}{100}$`)`
`=` $\frac{3}{2}$`(`$\frac{1}{2}$ `-` $\frac{1}{100}$`)`
`=` $\frac{3}{2}$`(`$\frac{50}{100}$ `-` $\frac{1}{100}$`)`
`=` $\frac{3}{2}$.$\frac{49}{100}$
`=` $\frac{147}{200}$
