Tính:
a. \(\dfrac{-5}{14}-\dfrac{2}{14}+\dfrac{1}{8}+\dfrac{1}{8}\)
b.\(\dfrac{-5}{22}-1+\dfrac{3}{2}-\dfrac{6}{22}\)
c.\(\dfrac{2}{5}+\dfrac{5}{4}+(\dfrac{-2}{5}+\dfrac{5}{4})-\dfrac{5}{2}\)
d.\(\dfrac{-1}{2}+\dfrac{1}{4}+\dfrac{2}{8}-\dfrac{11}{77}\)
làm nhanh hộ mình nha!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
a,\(\dfrac{-5}{14}\)-\(\dfrac{2}{14}\)+\(\dfrac{1}{8}\)+\(\dfrac{1}{8}\)
= (\(\dfrac{-5}{14}\) - \(\dfrac{2}{14}\)) + \(\dfrac{1}{4}\)
= \(\dfrac{-1}{2}\)+\(\dfrac{1}{4}\) = - \(\dfrac{1}{4}\)
b,\(\dfrac{-5}{22}-1+\dfrac{3}{2}-\dfrac{6}{22}\)
=\(\left(\dfrac{-5}{22}-\dfrac{6}{22}\right)-1+\dfrac{3}{2}\)
=\(\dfrac{-1}{2}-1+\dfrac{3}{2}\)
=\(\left(\dfrac{-1}{2}+\dfrac{3}{2}\right)-1\)
\(=1-1=0\)
c,\(\dfrac{2}{5}+\dfrac{5}{4}+\left(\dfrac{-2}{5}+\dfrac{5}{4}\right)-\dfrac{5}{2}\)
\(=\dfrac{2}{5}+\dfrac{5}{4}+\dfrac{-2}{5}+\dfrac{5}{4}-\dfrac{5}{2}\)
\(=\left(\dfrac{2}{5}+\dfrac{-2}{5}\right)+\left(\dfrac{5}{4}+\dfrac{5}{4}\right)-\dfrac{5}{2}\)
\(=0+\dfrac{5}{2}-\dfrac{5}{2}=0\)
Tạm 2 phần nè,xíu cho 2 phần kia nghe
\(d,\dfrac{-1}{2}+\dfrac{1}{4}+\dfrac{2}{8}-\dfrac{11}{77}\)
\(=\left(\dfrac{-1}{2}+\dfrac{1}{4}+\dfrac{2}{8}\right)-\dfrac{1}{7}\)
\(=0-\dfrac{1}{7}=-\dfrac{1}{7}\)
nàng nhớ follow ta nha.
