1, \(\frac{5}{21}+0,5-\frac{19}{23}+\frac{16}{21}-\frac{4}{23}\)

\(=\frac{5+16}{21}-\frac{19+4}{23}+0,5\)

\(=1-1+0,5\)

\(=0,5\)

2,\(\frac{27}{23}+\frac{5}{21}-\frac{4}{23}+\frac{6}{21}+\frac{1}{2}\)

\(=\frac{27-4}{23}+\frac{5+6}{21}+\frac{1}{2}\)

\(=1+\frac{11}{21}+\frac{1}{2}\)

\(=\frac{42+22+21}{42}\)

\(=\frac{85}{42}\)

= 5/2

( 27/23 - 4/23 ) + ( 5/21 + 6/21 ) + 1/2 = 1 + 11/21 +1/2 = 85/42

hình như bạn ghi có chút nhầm lẫn !

27/23 + 5/21 - 4/23 + 6/21 + 1/2

=> A = ( 27/23 - 4/23 ) + ( 5/21 + 6/21 ) + 1/2

=> A = 1 + 1 + 1/2

<=> A = 5/2

~ ủng hộ mk nha ~

\(\dfrac{27}{23}+\dfrac{5}{21}-\dfrac{4}{23}+\dfrac{6}{21}-\dfrac{1}{2}\)

\(=\left(\dfrac{27}{23}-\dfrac{4}{23}\right)+\left(\dfrac{5}{21}+\dfrac{6}{21}\right)-\dfrac{1}{2}\)

\(=1+\dfrac{11}{21}-\dfrac{1}{2}\)

\(=\dfrac{32}{21}-\dfrac{1}{2}\)

\(=\dfrac{43}{42}\)

\(\left(\frac{27}{23}-\frac{4}{23}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+\frac{1}{2}\)

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

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

k cho mk nha!

Bài 1:

1: =15+37+52-37-17=52-2=50

2: =38-42+14-25+27+15=62-42+29=20+29=49

Bài 1: Bỏ ngoặc rồi tính

3) (21-32) - (-12+32)=21-32-(-12)-32=21-32+12-32=-31

4) (12+21) - (23-21+10)=12+21-23+21-10=21

5) (57-725) - (605-53)=57-725-605+53=-1220

6) (55+45+15) - (15-55+45)=55+45+15-15+55-45=55+55=110

Bài 2: Tính các tổng sau một cách hợp lí

1) (-37) + 14 + 26 + 37=(-37+37)+(14+26)=0+40=40

2) (-24) +6 + 10 + 24=(-24+24)+(6+10)=0+16=16

3) 15 + 23 + (-25) + (-23)=(15-25)+(23-23)=-10+0=-10

4) 60 + 33 + (-50) + (-33)=(60-50)+(33-33)=10+0=10

5) (-16) + (-209) + (-14) + 209=(-16-14)+(-209+209)=-30+0=-30

6) (-12) + (-13) + 36 + (-11)=(-11-12-13)+36=-36+36=0

=15+37+52-37-17 =(37-37)+52+15-17 =0+52+15-17 =67-17 =50

(38 – 42 + 14) – (25 – 27 – 15) =38-42+14-25+27+15 =27 c. -(21 – 32) – (-12 + 32) =-21+32+12-32 =-9 d. -(12 + 21 – 23) - (23 – 21 + 10) =-12-21+23-23+21-10 =-22 e. (57 – 725) – (605 – 53) =57-725-605+53 =-1220 f. (55 + 45 + 15) – (15 – 55 + 45) =55+45+15-15+55-45 =110

Bài 1:

a, Ta có: \(\dfrac{27}{23}+\dfrac{5}{21}-\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}\)

= \(\left(\dfrac{27}{23}-\dfrac{4}{23}\right)+\left(\dfrac{5}{21}+\dfrac{16}{21}\right)+\dfrac{1}{2}\)

=\(\dfrac{23}{23}+\dfrac{21}{21}+\dfrac{1}{2}\) = \(1+1+\dfrac{1}{2}\)

= \(2\dfrac{1}{2}\)

b: \(=\dfrac{3}{2}-\dfrac{5}{6}:\dfrac{1}{4}+2=\dfrac{7}{2}-\dfrac{5}{6}\cdot4=\dfrac{7}{2}-\dfrac{10}{3}\)

\(=\dfrac{21-20}{6}=\dfrac{1}{6}\)

a: \(=\left(\dfrac{27}{23}-\dfrac{4}{23}\right)+\left(\dfrac{5}{21}+\dfrac{16}{21}\right)+\dfrac{1}{2}=2+\dfrac{1}{2}=\dfrac{5}{2}\)

(-3/4+2/3):5/11+(-1/4+1/3):5/11

a)|x-13|-35-45=-47

b)(4+x).(x+3)=0

c)25-(5-x)=120-(28-5)

\(\Rightarrow A=\left(\frac{27}{23}-\frac{4}{23}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+\frac{1}{2}\)

\(\Rightarrow A=1+1+\frac{1}{2}\)

\(\Rightarrow A=\frac{5}{2}\)

tíc mình nha

A=1+1+1/2

A=5/2

=5/2 nhé