Question

tính nhanh phép tính sau -5/9 + 8/ 15 + -2/11 + 4/-9 + 7/15

Answer 1

\(\dfrac{-5}{9}+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}\)

=\(\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)-\dfrac{2}{11}\)

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

Answer 2

\(=\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)+\dfrac{-2}{11}\\ =-1+1+\dfrac{-2}{11}\\ =0+\dfrac{-2}{11}=\dfrac{-2}{11}\)

Answer 3

\(\dfrac{-5}{9}+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}\)

 

\(=\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)+\dfrac{-2}{11}\)

 

\(=\dfrac{-9}{9}+\dfrac{15}{15}+\dfrac{-2}{11}\)

 

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

 

\(=0+\dfrac{-2}{11}\)

 

\(=\) \(\dfrac{-2}{11}\)

Answer 4

\(\dfrac{-5}{9}\)+\(\dfrac{8}{15}\)+\(\dfrac{-2}{11}\)+\(\dfrac{4}{-9}\)+\(\dfrac{7}{15}\)=(\(\dfrac{-5}{9}\)+\(\dfrac{-4}{9}\))+(\(\dfrac{7}{15}\)+\(\dfrac{8}{15}\))+\(\dfrac{-2}{11}\)

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

                                     =                  0              +\(\dfrac{-2}{11}\)

                                     =                     \(\dfrac{-2}{11}\)

Thấy đúng thì cho mik 1 đúng và 1 theo dõi nhé! ( ͡◉ ͜ʖ ͡◉)