c)
\(-\dfrac{3}{5}.\dfrac{2}{7}+-\dfrac{3}{5}.\dfrac{5}{7}-\dfrac{-13}{5}\\ =-\dfrac{3}{5}\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{13}{5}\\ =-\dfrac{3}{5}.1+\dfrac{13}{5}\\ =-\dfrac{3}{5}+\dfrac{13}{5}\\ =\dfrac{13-3}{5}\\ =\dfrac{10}{5}\\ =2\)
d)
\(\dfrac{8}{15}.\dfrac{-13}{27}+\dfrac{8}{15}.\dfrac{-14}{27}+1\dfrac{2}{3}\\ =\dfrac{8}{15}\left(-\dfrac{13}{27}-\dfrac{14}{27}\right)+\dfrac{5}{3}\\ =\dfrac{8}{15}.-1+\dfrac{5}{3}\\ =-\dfrac{8}{15}+\dfrac{5.5}{15}\\ =\dfrac{25-8}{15}\\ =\dfrac{17}{15}\)
C.
=-3/5 . (2/7+5/7) + 13/5
=-3/5 (7/7) + 13/5
-3/5 + 13/5
=10/5
=2
d.
=8/15(-13/27 - 14/27) + 5/3
=8/15 . (-27/27) + 5/3
=-8/15 + 5/3
=-8/15 + 25/15
=17/15
mọi người làm cho em câu c , d với ạ
làm mỗi câu d thôi ạ
mọi người làm cho em câu d bài 2 với ạ
