a) \(A=\dfrac{7}{8}\left(-\dfrac{5}{9}-\dfrac{4}{9}\right)+5\dfrac{7}{8}\)
\(A=\dfrac{7}{8}.\left(-1\right)+5\dfrac{7}{8}=5\dfrac{7}{8}-\dfrac{7}{8}=5\).
\(B=\dfrac{1}{4}.\dfrac{8}{5}.\dfrac{25}{16}.\dfrac{-7}{4}=\dfrac{-35}{32}\)
a) \(A=\dfrac{-7}{8}.\dfrac{5}{9}-\dfrac{4}{9}.\dfrac{7}{8}+5\dfrac{7}{8}\)
\(A=\dfrac{7}{8}.\left(\dfrac{-5}{9}-\dfrac{4}{9}\right)+\dfrac{47}{8}\)
\(A=\dfrac{7}{8}.-1+\dfrac{47}{8}\)
\(A=\dfrac{-7}{8}+\dfrac{47}{8}\)
\(A=5\)
b) \(B=0,25.1\dfrac{3}{5}.\left(\dfrac{5}{4}\right)^2:\left(\dfrac{-4}{7}\right)\)
\(B=\dfrac{1}{4}.\dfrac{8}{5}.\dfrac{25}{16}.\dfrac{-7}{4}\)
\(B=\dfrac{-35}{32}\)