Question

Tính bằng cách hợp lí:

a, -10/11 . 8/9 + 7/18 . 10/11

b, -1\(\frac{5}{7}\). 15 + 2/7 . (-15) + (-105) . (2/3 - 4/5 +1/7)

 

 

 

 

Answer 1

a) \(-\frac{10}{11}.\frac{8}{9}+\frac{1}{18}\left(-\frac{10}{11}\right)\)

\(=\left(-\frac{10}{11}\right)^2.\left(\frac{8}{9}+\frac{1}{18}\right)\)

\(=\frac{100}{121}.\frac{17}{18}\)

\(=\frac{850}{1089}\)

bn ghi sai đề rồi

Answer 2

a 10/11x-8/9+7/18x10/11

   10/11x(-8/9+7/18)

   10/11x-1/9=-10/99

sorry mình ko biết làm câu b