\(=\dfrac{5}{21}+\dfrac{16}{21}-\left(\dfrac{19}{23}+\dfrac{4}{23}\right)+\dfrac{1}{2}=\dfrac{1}{2}\)

=27/23+5/21-4/23+1/2+16/21

=682/483-4/23+1/2+16/21

=26/21+1/2+16/21

=5/2

=1+4/23-4/23+5/21+16/21+1/2

=1+1+1/2

=5/2

\(\dfrac{27}{23}\) + \(\dfrac{5}{21}\) - \(\dfrac{4}{23}\) + \(0,5\) + \(\dfrac{16}{21}\)

= [ \(\dfrac{27}{23}\) - \(\dfrac{4}{23}\) ] + [ \(\dfrac{5}{21}\) + \(\dfrac{16}{21}\) ] + 0,5

=  1 + 1 + 0,5 

=  2 + 0,5

=  2,5

= 5/2

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

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

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

k cho mk nha!

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

Chúc học tốt!!!

bạn ghi rõ được ko

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

=1-1+0,5

=0,5

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)