Question

Cho biểu thức:
\(A=\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
tính bằng 2 cách:

cách 1:trước hết, tính giá trị của từng biểu thức trong ngoặc
cách 2:bỏ dấu ngoặc rồi nhóm các số hạng thích hợp

Answer 1

Cách 1:
\(A=\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
  \(=\left(\frac{36}{6}-\frac{4}{6}+\frac{3}{6}\right)-\left(\frac{30}{6}+\frac{10}{6}-\frac{9}{6}\right)-\left(\frac{18}{6}-\frac{14}{6}+\frac{15}{6}\right)\)
  \(=\frac{35}{6}-\frac{31}{6}-\frac{19}{6}\)
  \(=-\frac{15}{6}\)
  \(=-\frac{5}{2}\)

Cách 2:
\(A=\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
  \(=6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)
  \(=\left(6-5-3\right)+\left(-\frac{2}{3}-\frac{5}{3}+\frac{7}{3}\right)+\left(\frac{1}{2}+\frac{3}{2}-\frac{5}{2}\right)\)
  \(=-2+0-\frac{1}{2}\)
  \(=-\frac{4}{2}-\frac{1}{2}\)
  \(=-\frac{5}{2}\)

Answer 2

C1
23+12)−(5+53−32)−(3−73+52)=(6.66−2.26+36)−(5.66+5.26−3.36)−(3.66−7.26+5.36)=36−4+36−30+10−96−18−14+156=356−316−196=35−31−196=−156=−52=−212.

23+12)−(5+53−32)−(3−73+52)=6−23+12−5−53+32−3+73−52=(6−5−3)+(−23−53+73)+(12+32−52)=−2+−2−5+73+1+3−52=−2+0−12=−52=−212." role="presentation" style="border:0px; direction:ltr; display:inline-block; float:none; font-size:16.94px; line-height:0; margin:0px; max-height:none; max-width:none; min-height:0px; min-width:0px; overflow-wrap:normal; padding:1px 0px; position:relative; white-space:nowrap; word-spacing:normal" class="MathJax_CHTML mjx-chtml">A=(6−23+12)−(5+53−32)−(3−73+52)=6−23+12−5−53+32−3+73−52=(6−5−3)+(−23−53+73)+(12+32−52)=−2+−2−5+73+1+3−52=−2+0−12=−52=−212