Question

[Call Me_MOSTER]

Cho biểu thức:
(\(6-\frac{2}{3}+\frac{1}{2}\))  - \(\left(5+\frac{5}{3}-\frac{3}{2}\right)\)- \(\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
Em hãy tính bằng 2 cách:
c1: tính giá trị của biểu thức trong ngoặc
c2: bỏ dấu nguặc rồi nhóm các số hang thích hợp 
 

Answer 1

[Hà Hà]

Cách 1:

\(\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)

\(=\left(\frac{36-4+3}{6}\right)-\left(\frac{30+10-9}{6}\right)-\left(\frac{18-14+15}{6}\right)\)

\(=\frac{35}{6}-\frac{31}{6}-\frac{19}{6}\)

\(=\frac{35-31-19}{6}\)

\(=\frac{-15}{6}=\frac{-5}{2}\)

Cách 2:

\(\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)

\(=6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)

\(=6-5-3+\frac{1}{2}+\frac{3}{2}-\frac{5}{2}-\frac{2}{3}-\frac{5}{3}+\frac{7}{3}\)

\(=-2-\frac{1}{2}+0\)

\(=\frac{-5}{2}\)

Answer 2

[Trần Đức Thắng]

= \(6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)

\(=\left(-\frac{2}{3}-\frac{5}{3}+\frac{7}{3}\right)+\left(\frac{1}{2}+\frac{3}{2}-\frac{5}{2}\right)+\left(6-5-3\right)=0-\frac{1}{2}-2=-\frac{5}{2}\)