$\text{Bài 1.}$
$\frac{25}{50}$ = $\frac{25:25}{50:25}$ = $\frac{1}{2}$
$\frac{15}{120}$ = $\frac{15:15}{120:15}$ = $\frac{1}{8}$
$\frac{64}{720}$ = $\frac{64:16}{720:16}$ = $\frac{4}{45}$
$\frac{5}{25}$ = $\frac{5:5}{25:5}$ = $\frac{1}{5}$
$\frac{36}{48}$ $\frac{36:12}{48:12}$ = $\frac{3}{4}$
$\frac{84}{126}$ = $\frac{84:42}{126:42}$ = $\frac{2}{3}$
$\text{HSNK:}$
$\frac{414141}{494949}$ = $\frac{414141:10101}{494949:10101}$ = $\frac{41}{49}$
$\frac{171717171}{180180180}$ = $\frac{171717171:15}{180180180:15}$ = $\frac{1144781}{12012012}$
$\text{Bài 2. Viết số thích hợp vào ô trống:}$
` 160/320 = 16/32 = 8/16 = 4/8 = 1/2 `
$\text{Bài 3 trong hình nha bạn.}$
$\text{@cindy}$
$\text{#nocopy}$