\(a,\left(\dfrac{3}{8}-\dfrac{1}{5}-\dfrac{1}{3}\right)+\left(\dfrac{5}{8}-1\dfrac{3}{7}-\dfrac{4}{7}\right)+\dfrac{1}{3}\\ =\dfrac{3}{8}-\dfrac{1}{5}-\dfrac{1}{3}+\dfrac{5}{8}-\dfrac{10}{7}-\dfrac{4}{7}\\ =\left(\dfrac{3}{8}+\dfrac{5}{8}\right)-\left(\dfrac{1}{5}+\dfrac{1}{3}-\dfrac{1}{3}\right)-\left(\dfrac{10}{7}+\dfrac{4}{7}\right)\\ =1-\dfrac{1}{5}-2=\left(1-2\right)-\dfrac{1}{5}\\ =-1-\dfrac{1}{5}=-\dfrac{6}{5}\)
\(b,-24\left(\dfrac{1}{3}-\dfrac{1}{4}\right)^2-1,5\\ =-24\left(\dfrac{4}{12}-\dfrac{3}{12}\right)^2-\dfrac{3}{2}\\ =-24\left(\dfrac{1}{12}\right)^2-\dfrac{3}{2}\\ =-24\cdot\dfrac{1}{144}-\dfrac{3}{2}\\ =-\dfrac{2}{37}-\dfrac{3}{2}=\dfrac{4}{74}-\dfrac{111}{74}\\ =\dfrac{-115}{74}\)
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