a) \(6.\left(-3\right)+\left(-4\right).\left(-5\right)=\left(-18\right)+20=2\)
b) \(\dfrac{2}{5}-\dfrac{1}{3}=\dfrac{6}{15}-\dfrac{5}{15}=\dfrac{1}{15}\) ( cái này hình như k chuyển dc thành hỗn số bn à)
c) \(\dfrac{-3}{5}.\dfrac{4}{7}+\dfrac{3}{7}.\dfrac{-3}{5}+\dfrac{3}{5}\)\(=\dfrac{-3}{5}.\dfrac{4}{7}+\dfrac{3}{7}.\dfrac{-3}{5}+\left(-1\right).\dfrac{-3}{5}\)
\(=\dfrac{-3}{5}.\left(\dfrac{4}{7}+\dfrac{3}{7}+\left(-1\right)\right)=\dfrac{-3}{5}.0=0\)
Chúc bn học tốt
\(a,6.\left(-3\right)+\left(-4\right).\left(-5\right)\)
\(=-18+20\)
\(=2\)
\(b,2\dfrac{3}{5}-1\dfrac{2}{3}\)
\(=\dfrac{13}{5}-\dfrac{5}{3}\)
=\(\dfrac{14}{15}\)
\(c,\dfrac{-3}{5}.\dfrac{4}{7}+\dfrac{3}{7}.\dfrac{-3}{5}+\dfrac{3}{5}\)
\(=\dfrac{-3}{5}.\left[\dfrac{4}{7}+\dfrac{3}{7}+\left(-1\right)\right]\)
\(=\dfrac{-3}{5}.0\)
\(=0\)
