`6/21-(-12/44)+10/14-(1/(-4))-18/33`

`=2/7+12/44+5/7-((-1)/4)-6/11`

`=2/7+3/11+5/7+1/4-6/11`

`=(3/11-6/11)+(2/7+5/7)+1/4`

`=-3/11+7/7+1/4`

`=43/44`

chỗ này là dấu gì thế, hay là 2 phép tính khác nhau ?

?

= 43/44

Đáp án : 43/44

= \(\dfrac{2}{7}\) - \(\dfrac{-3}{11}\)+\(\dfrac{5}{7}\)-\(\dfrac{-1}{4}\)- \(\dfrac{6}{11}\)

= (\(\dfrac{2}{7}\)+\(\dfrac{5}{7}\)) - ( \(\dfrac{-3}{11}\)+ \(\dfrac{6}{11}\)) - \(\dfrac{-1}{4}\)

= 1 - \(\dfrac{3}{11}\)-\(\dfrac{-1}{4}\)

= \(\dfrac{44}{44}\)-\(\dfrac{12}{44}\)-\(\dfrac{-11}{44}\)

= \(\dfrac{43}{44}\)

=(2/7+5/7)+(3/11-6/11)+1/4

=5/4-3/11

=55/44-12/44=43/44

Câu 1:

\(=\dfrac{21}{31}+\dfrac{1}{3}-\dfrac{44}{53}+\dfrac{10}{31}-\dfrac{9}{53}=\dfrac{1}{3}\)

Câu 2:

1: =>1,3x=-1,31

=>130x=-131

=>x=-131/130

2: =>(4,5-2x)=11/14:(-11/7)=-7/14=-1/2=-0,5

=>2x=5

=>x=5/2

=(2/7+5/7)+(3/11-6/11)+1/4

=5/4-3/11=55/44-12/44=43/44

B. 173 + 45 + 135 + 27 + 50 

= (173+27) + (45 +135) +50

=200 + 180 + 20 + 30

= 200 +200 +30

=430

bằng 500 chứ câu a ấy

A. 35+156+21+75+179+44

=(35+75)+(156+44)+(21+179)

=100+200+200

=500

B.173+45+135+27+50

=(173+27)+(45+125)+50

=200+180+20+30

=200+200+30

=430

\(\frac{6}{21}-\left(-\frac{12}{44}\right)+\frac{10}{14}-\frac{1}{-4}-\frac{18}{33}\)

\(=\frac{3}{7}-\left(-\frac{3}{11}\right)+\frac{5}{7}+\frac{1}{4}-\frac{6}{11}\)

sai đề