Question

1. Tính (bằng cách hợp lý nhất0

a, -2/5. 4/7 + -3/5 . 2/7 + -3/5

b,5/9.14/17+1/17.5/9+ 2/9 . 5/12

c,-4/25: 11/79 +15/11:25/79

d, (2/101: -5/9 + -3/7). (6/5-2/5:1/3)

Please help me!!!

 

Answer 1

a)=\(\frac{-2.4}{5.7}+\frac{-3.2}{5.7}+\frac{-3}{5}\)

=\(\frac{-2.4}{5.7}+\frac{-2.3}{5.7}+\frac{-3}{5}\)

=\(\frac{-2}{5}\left(\frac{4+3}{7}\right)+\frac{-3}{5}\)

=\(\frac{-2}{5}.1+\frac{-3}{5}\)

=-1

b)

Answer 2

Giúp mình các câu khác với ngo vinh thien 

please!!