a: \(-\dfrac{5}{4}:\left(\dfrac{1}{4}-\dfrac{7}{8}\right)+\dfrac{3}{2}\left(\dfrac{1}{3}-\dfrac{5}{6}\right)\)
\(=-\dfrac{5}{4}:\dfrac{2-7}{8}+\dfrac{3}{2}\cdot\dfrac{2-5}{6}\)
\(=-\dfrac{5}{4}\cdot\dfrac{8}{-5}+\dfrac{3}{2}\cdot\dfrac{-3}{6}\)
\(=2-\dfrac{3}{4}=\dfrac{5}{4}\)
b: \(\dfrac{1}{3}:\left(0,75+\dfrac{1}{3}\right)-50\%\cdot1\)
\(=\dfrac{1}{3}:\left(\dfrac{3}{4}+\dfrac{1}{3}\right)-\dfrac{1}{2}\)
\(=\dfrac{1}{3}:\dfrac{13}{12}-\dfrac{1}{2}=\dfrac{1}{3}\cdot\dfrac{12}{13}-\dfrac{1}{2}=\dfrac{4}{13}-\dfrac{1}{2}\)
\(=\dfrac{8}{26}-\dfrac{13}{26}=-\dfrac{5}{26}\)
c: \(\dfrac{8}{11}+\dfrac{-6}{11}\cdot\dfrac{4}{13}-\dfrac{4}{11}\cdot\dfrac{7}{13}\)
\(=\dfrac{8}{11}+\dfrac{4}{11}\left(-\dfrac{6}{13}-\dfrac{7}{13}\right)\)
\(=\dfrac{8}{11}-\dfrac{4}{11}=\dfrac{4}{11}\)
d:\(\left(-2,5\right)\cdot0,65-1,5\cdot0,3+\left(-0,35\right)\cdot1,5\)
\(=-2,5\cdot0,65+1,5\left(-0,3-0,35\right)\)
\(=-2,5\cdot0,65+1,5\cdot\left(-0,65\right)\)
\(=\left(-0,65\right)\left(2,5+1,5\right)=-0,65\cdot4=-2,6\)
a, = -5/4 : (2/8 - 7/8) + 3/2 ( 2/6 - 5/6)
= -5/4 : (-5/8) + 3/2.(-1/2)
= 8/4 - 3/4 = 5/4
