Question

2/9 + 1/5 + 7/9 + 4/5

7/19 x 1/3 + 7/19 x 2/3

33,76 + 19,52 + 6,24

24 x 57 + 43 x 24

Answer 1

\(\dfrac{2}{9}+\dfrac{1}{5}+\dfrac{7}{9}+\dfrac{4}{5}=\left(\dfrac{2}{9}+\dfrac{7}{9}\right)+\left(\dfrac{1}{5}+\dfrac{4}{5}\right)=1+1=2\)

\(\dfrac{7}{19}\times\dfrac{1}{3}+\dfrac{7}{19}\times\dfrac{2}{3}=\dfrac{7}{19}\times\left(\dfrac{1}{3}+\dfrac{2}{3}\right)=\dfrac{7}{19}\times1=\dfrac{7}{19}\)

\(33,76+19,52+6,24=\left(33,76+6,24\right)+19,52=40+19,52=59,52\)

\(24\times57+43\times24=24\times\left(57+43\right)=24\times100=2400\)

Answer 2

a: =2/9+7/9+1/5+4/5

=1+1=2

b: =7/19(2/3+1/3)=7/19

c: =40+19,52=59,52

d: =24(57+43)=24x100=2400

Answer 3

2/9 + 1/5 + 7/9 + 4/5=(2/9+7/9)+(1/5+4/5)=1+1=2

7/19 x 1/3 + 7/19 x 2/3=7/19x(1/3+2/3)=7/19x1=7/19

33,76 + 19,52 + 6,24=33,76+6,24+19,52=40+19,52=59,52

24 x 57 + 43 x 24=24x(57+43)=24x100=2400