3 2   -   4 8   =   3 2   -   1 2   =   2 2   =   1

a, 48/64 + 7/4 

 = 3/4 + 7/4

 = 10/4

b, 3/8 + 119/56

= 3/8 + 17/8

= 20/8

a)48/64=3/4

3/4+7/4=10/4=5/2

b) 119/56=119:7/56:7=17/8

3/8+17/8=20/8=5/2

k mk nghen ^.-

giúp mik đi mà các bạn ơi

2/3; 5/12; 37/50; 6/7; 20/27; 2/3

a: 78/42-4/7=13/7-4/7=9/7

100/110-56/88=10/11-7/11=3/11

75/35-11/7+21/49=15/7-11/7+3/7=7/7=1

99/72-15/40-1212/1616=11/8-3/8-3/4=1-3/4=1/4

a: \(\dfrac{8}{18}+\dfrac{5}{3}=\dfrac{4}{9}+\dfrac{5}{3}=\dfrac{4}{9}+\dfrac{15}{9}=\dfrac{4+15}{9}=\dfrac{19}{9}\)

b: \(\dfrac{8}{24}+\dfrac{4}{48}=\dfrac{1}{3}+\dfrac{1}{12}=\dfrac{4}{12}+\dfrac{1}{12}=\dfrac{4+1}{12}=\dfrac{5}{12}\)

c: \(\dfrac{20}{15}-\dfrac{4}{45}=\dfrac{4}{3}-\dfrac{4}{45}=\dfrac{60}{45}-\dfrac{4}{45}=\dfrac{60-4}{45}=\dfrac{56}{45}\)

d: \(\dfrac{40}{32}-\dfrac{1}{2}=\dfrac{5}{4}-\dfrac{1}{2}=\dfrac{5-2}{4}=\dfrac{3}{4}\)

\(\frac{9}{12}+\frac{4}{7}\)

\(=\frac{3}{4}+\frac{4}{7}\)

\(=\frac{37}{28}\)

\(\frac{5}{10}+\frac{21}{28}\)

\(=\frac{1}{2}+\frac{3}{4}\)

\(=\frac{5}{4}\)

\(\frac{7}{9}+\frac{15}{27}\)

\(=\frac{7}{9}+\frac{5}{9}\)

\(=\frac{12}{9}\)

9/12 + 4/7=37/28

5/10 + 21/28 = 5/4

7/9 + 15/27 = 4/3

90/70 và 72/42 nhé em gửi nó bị lỗi

nhầm nha 

a

920

12404

b 

872

1350

nha

hok tốt nha

nhớ k nha