Question

Bài 27: Tính

3/4+2/3;                         3/5+7/10;                      1/4+7/6

2/3-2/7;                          3/4-5/12;                        5/6-2/9

2+5/7;                             13/5-2                            3-3/8

1/2+1/3+1/6;                    5/12+5/6-3/4;                 1-(1/5+1/2)

Bài 102: Tính bằng cách thuận tiện nhất

a) 2/9+1/5+7/9+4/5

b) 1/12+3/16+5/12+5/16

Answer 1

Bài 27: Tính

3/4+2/3=17/12                        3/5+7/10=13/10         1/4+7/6=17/12

2/3-2/7=8/21                          3/4-5/12=1/3                  5/6-2/9=11/18

2+5/7=19/7                             13/5-2 = 3/5                   3-3/8=21/8

1/2+1/3+1/6=1                    5/12+5/6-3/4= 1/2              1-(1/5+1/2)=3/10.

 

tick cho mik vs ạ 

 

Answer 2

bài 1

\(\dfrac{3}{4}\)\(\text{+}\dfrac{2}{3}=\dfrac{17}{12}\)

\(\dfrac{2}{3}-\dfrac{2}{7}=\dfrac{8}{21}\)

\(2\text{+}\dfrac{5}{7}=\dfrac{19}{7}\)

\(\dfrac{1}{2}\text{+}\dfrac{1}{3}\text{+}\dfrac{1}{6}=\dfrac{5}{6}\text{+}\dfrac{1}{6}=\dfrac{5\text{+}1}{6}=\dfrac{6}{6}=1\)

\(\dfrac{3}{5}\text{+}\dfrac{7}{10}=\dfrac{13}{10}\)

\(\dfrac{3}{4}-\dfrac{5}{12}=\dfrac{1}{3}\)

\(\dfrac{13}{5}-2=\dfrac{3}{5}\)

\(\dfrac{5}{12}\text{+}\dfrac{5}{6}-\dfrac{3}{4}=\dfrac{5}{4}-\dfrac{3}{4}=\dfrac{5-3}{4}=\dfrac{2}{4}=\dfrac{1}{2}\)

\(\dfrac{1}{4}\text{+}\dfrac{7}{6}=\dfrac{17}{12}\)

\(\dfrac{5}{6}-\dfrac{2}{9}=\dfrac{11}{18}\)

\(3-\dfrac{3}{8}=\dfrac{21}{8}\)

\(1-\left(\dfrac{1}{5}\text{+}\dfrac{1}{2}\right)=1-\dfrac{7}{10}=\dfrac{3}{10}\)

 

Answer 3