Question

Thực hiện phép tính (hợp lí nếu có thể)

Answer 1

a: \(=\dfrac{3\cdot5-4\cdot7}{35}+\dfrac{4}{5}=\dfrac{15-28+28}{35}=\dfrac{15}{35}=\dfrac{3}{7}\)

e: \(=\dfrac{28}{15}\cdot\dfrac{3}{4}-\left(\dfrac{11}{20}+\dfrac{1}{4}\right)\cdot\dfrac{5}{7}=\dfrac{7}{5}-\dfrac{4}{5}\cdot\dfrac{5}{7}=\dfrac{7}{5}-\dfrac{4}{7}=\dfrac{49-20}{35}=\dfrac{29}{35}\)

i: =9/7+5/6-9/7=5/6