Cách 1 : Trước hết tính giá trị từng biểu thức trong ngoặc
\(-\left(4-\dfrac{1}{3}+\dfrac{3}{5}\right)-\left(3+\dfrac{2}{3}-\dfrac{4}{5}\right)+\left(5+\dfrac{4}{3}-\dfrac{4}{5}\right)\)
\(=-\left(\dfrac{60}{15}-\dfrac{5}{15}+\dfrac{9}{15}\right)-\left(\dfrac{45}{15}+\dfrac{10}{15}-\dfrac{20}{15}\right)+\left(\dfrac{75}{15}+\dfrac{20}{15}-\dfrac{12}{15}\right)\)
\(=-\left(\dfrac{64}{15}\right)-\left(\dfrac{35}{15}\right)+\left(\dfrac{83}{15}\right)\)
\(=-\dfrac{64}{15}-\dfrac{35}{15}+\dfrac{83}{15}\)
\(=-\dfrac{16}{15}\)
\(=-\dfrac{8}{5}\)
Cách 2 : Bỏ dấu ngoặc rồi nhóm các số hạng thích hợp
\(-\left(4-\dfrac{1}{3}+\dfrac{3}{5}\right)-\left(3+\dfrac{2}{3}-\dfrac{4}{5}\right)+\left(5+\dfrac{4}{3}-\dfrac{4}{5}\right)\)
\(=-4+\dfrac{1}{3}-\dfrac{3}{5}-3-\dfrac{2}{3}+\dfrac{4}{5}+5+\dfrac{4}{3}-\dfrac{4}{5}\)
\(=\left(-4-3+5\right)+\left(\dfrac{1}{3}-\dfrac{2}{3}+\dfrac{4}{3}\right)+\left(-\dfrac{3}{5}+\dfrac{4}{5}-\dfrac{4}{5}\right)\)
\(=-2+1-\dfrac{3}{5}\)
\(=-\dfrac{8}{5}\)
