\(\frac{19}{15}+\frac{31}{23}-\frac{4}{15}-\frac{8}{23}\)

\(=\left(\frac{19}{15}-\frac{4}{15}\right)+\left(\frac{31}{23}-\frac{8}{23}\right)\)

\(=\frac{15}{15}+\frac{23}{23}\)

\(=1+1=2\)

\(\frac{19}{15}+\frac{31}{23}-\frac{14}{15}-\frac{8}{23}\)

\(=\frac{19}{15}-\frac{4}{15}+\frac{31}{23}-\frac{8}{23}\)

\(=1+1=2\)

chúc bạn học giỏi

19 / 15 + 31 / 25 - 4 / 15 - 8 / 23

= ( 19 / 15 - 4 / 15 ) + ( 31 / 23 - 8 / 23 )

= 15 / 15 + 23 / 23

= 1 + 1 = 2

a) \(\frac{7}{18}+\frac{4}{23}+\frac{11}{18}+\frac{19}{23}\)

\(=\left(\frac{7}{18}+\frac{11}{18}\right)+\left(\frac{4}{23}+\frac{19}{23}\right)\)

\(=1+1\)

\(=2\)

b) \(\frac{19}{15}+\frac{31}{23}-\frac{4}{15}-\frac{8}{23}\)

\(=\left(\frac{19}{15}-\frac{4}{15}\right)+\left(\frac{31}{23}-\frac{8}{23}\right)\)

\(=1+1\)

\(=2\)

ủng hộ tớ nha

a) (7/18+11/18)+(4/23+19/23)

=18/18+23/23

=1+1

=2

b)=2

\(a,b=2\)

nhiều thế

sfdhg 

\(\dfrac{1}{2}\) xy=\(\dfrac{17}{42}\)

=\(\dfrac{17}{42}\):\(\dfrac{1}{2}\)

= \(\dfrac{34}{42}\)

a) = \(\left(\dfrac{2}{7}+\dfrac{4}{7}+\dfrac{1}{7}\right):\dfrac{27}{31}\)

= \(\dfrac{7}{7}\) x \(\dfrac{31}{27}\)

= 1 x \(\dfrac{31}{27}\) = \(\dfrac{31}{27}\)

b) = \(\left(\dfrac{23}{45}:\dfrac{23}{45}\right)\)x \(\dfrac{17}{51}\)

= 1 x \(\dfrac{17}{51}\)= \(\dfrac{17}{51}\)

\(\dfrac{15}{18}+\dfrac{8}{23}+\dfrac{3}{18}+\dfrac{15}{23}=\left(\dfrac{15}{18}+\dfrac{3}{18}\right)+\left(\dfrac{8}{23}+\dfrac{15}{23}\right)=1+1=2\)

\(\dfrac{15}{18}+\dfrac{8}{23}+\dfrac{3}{18}+\dfrac{15}{23}\)

\(=(\dfrac{15}{18}+\dfrac{3}{18})+(\dfrac{8}{23}+\dfrac{15}{23})\)

\(=1+1\)

\(=2\)

=11/6*(15/23-7/23)
=11/6*8/23
=44/69
chúc bn hk tốt

\(\frac{11}{6}\times\frac{15}{23}-\frac{11}{6}\times\frac{7}{23}\)=  \(\frac{11}{6}\times\left(\frac{15}{23}-\frac{7}{23}\right)\)

                                                       =\(\frac{11}{6}\times\frac{8}{23}\)

                                                       =  \(\frac{44}{69}\)