Phép cộng phân số (tiếp theo)

Đề thiếu rồi bạn

ko phải đề thiếu đâu , đề thế mà

\(\dfrac{9}{15}+\dfrac{30}{100}+2=\dfrac{3}{5}+\dfrac{3}{10}+2=\dfrac{6}{10}+\dfrac{3}{10}+\dfrac{20}{10}=\dfrac{29}{10}\)

29/10

\(a.\dfrac{4}{8}+\dfrac{5}{4}=\dfrac{4+10}{8}=\dfrac{14}{8}=\dfrac{7}{4}.\\ b.\dfrac{12}{18}+\dfrac{15}{20}=\dfrac{2}{3}+\dfrac{3}{4}=\dfrac{8+9}{12}=\dfrac{17}{12}.\)

a)4/8+5/4=16/32+40/32=56/32=7/4

b)12/18+15/20=120/180+135/180=255/135=17/9

chiều rộng của hình chữ nhật:
35/15 - 6/5 = 17/15 (m)

TK : 

chiều rộng của hình chữ nhật:
35/15 - 6/5 = 17/15 (m)

Đ/S : 17/15 m 

17/15 m

a \(\dfrac{3}{2}\)

b \(\dfrac{8}{3}\)

a) \(\dfrac{5}{12}+\dfrac{3}{4}+\dfrac{1}{3}=\dfrac{5}{12}+\dfrac{9}{12}+\dfrac{4}{12}=\dfrac{18}{12}=\dfrac{3}{2}\)

b) \(\dfrac{4}{9}+\dfrac{25}{18}+\dfrac{5}{6}=\dfrac{8}{18}+\dfrac{25}{18}+\dfrac{15}{18}=\dfrac{48}{18}=\dfrac{8}{3}\)

7/6

7/6

7/6

=80/90+81/90=161/90

\(\dfrac{8}{9}+\dfrac{9}{10}=\dfrac{80}{90}+\dfrac{81}{90}=\dfrac{161}{90}\)\(=...\)

161/90

\(=\dfrac{17}{15}\)

\(\frac{17}{15}\)

17/15

31/32

\(\dfrac{31}{32}\)

31/12

4/5

1/5 + 1/2 + 1/10

= 7/10 + 1/10

= 8/10

= 4/5

\(\dfrac{1}{5}\) + \(\dfrac{1}{2}\) + \(\dfrac{1}{10}\)

\(=\) \(\dfrac{7}{10}\) + \(\dfrac{1}{10}\)

\(=\) \(\dfrac{8}{10}\)

\(=\) \(\dfrac{4}{5}\)