Rút gọn các phân số: 4/6, 12/8, 15/25, 11/22

Giải Toán lớp 4 Bài: Rút gọn phân số

Toán lớp 4 trang 114 Bài 1:

a) $\frac{4}{6};\frac{12}{8};\frac{15}{25};\frac{11}{22};\frac{36}{10};\frac{75}{36}$              

b)  $\frac{5}{10};\frac{12}{36};\frac{9}{72};\frac{75}{300};\frac{15}{35};\frac{4}{100}$

Lời giải

a)

$\frac{4}{6}=\frac{4:2}{6:2}=\frac{2}{3}\frac{12}{8}=\frac{12:4}{8:4}=\frac{3}{2}\frac{15}{25}=\frac{15:5}{25:5}=\frac{3}{5}\frac{11}{22}=\frac{11:11}{22:11}=\frac{1}{2}\frac{36}{10}=\frac{36:2}{10:2}=\frac{18}{5}\frac{75}{36}=\frac{75:3}{36:3}=\frac{25}{12}$                                                         

b)

$\frac{5}{10}=\frac{5:5}{10:5}=\frac{1}{2}\frac{12}{36}=\frac{12:12}{36:12}=\frac{1}{3}\frac{9}{72}=\frac{9:9}{72:9}=\frac{1}{8}\frac{75}{300}=\frac{75:75}{300:75}=\frac{1}{4}\frac{15}{35}=\frac{15:5}{35:5}=\frac{3}{7}\frac{4}{100}=\frac{4:4}{100:4}=\frac{1}{25}$