a) \(\left(-\dfrac{1}{2}\right)-\left(-\dfrac{3}{5}\right)+\left(-\dfrac{1}{5}\right)+\dfrac{1}{131}-\left(-\dfrac{2}{7}\right)+\dfrac{4}{35}-\dfrac{7}{18}\\ =-\dfrac{1}{2}+\dfrac{3}{5}-\dfrac{1}{5}+\dfrac{1}{131}+\dfrac{2}{7}+\dfrac{4}{35}-\dfrac{7}{18}\\ =\left(\dfrac{3}{5}-\dfrac{1}{5}+\dfrac{2}{7}+\dfrac{4}{35}\right)-\left(\dfrac{1}{2}+\dfrac{7}{18}\right)+\dfrac{1}{131}\\ =\dfrac{4}{5}-\dfrac{8}{9}+\dfrac{1}{131}=-\dfrac{4}{45}+\dfrac{1}{131}\\ =-\dfrac{479}{5895}\)
LÀM ƠN!!!!!!!! GIÚP MÌNH VỚI!!!!!!!!!!!!!!!!!