Question

tính nhanh

(-13/7-4/9)-(-10/7-4/9)

Answer 1

\(=-\dfrac{13}{7}-\dfrac{4}{9}+\dfrac{10}{7}+\dfrac{4}{9}\\ =\left(-\dfrac{4}{9}+\dfrac{4}{9}\right)+\left(-\dfrac{13}{7}+\dfrac{10}{7}\right)\\ =0-\dfrac{3}{7}=-\dfrac{3}{7}\)

Answer 2

\(=-\dfrac{13}{7}-\dfrac{4}{9}+\dfrac{10}{7}+\dfrac{4}{9}=\left(-\dfrac{13}{7}+\dfrac{10}{7}\right)+\left(-\dfrac{4}{9}+\dfrac{4}{9}\right)=-\dfrac{3}{7}+0=-\dfrac{3}{7}\)