\(\sqrt{13}\)

\(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{3}{7}\)

\(\frac{15}{34}+\frac{1}{3}+\frac{19}{34}+\left(-\frac{4}{3}\right)+\frac{3}{7}\)

\(\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{1}{3}-\frac{4}{3}\right)+\frac{3}{7}\)

\(1+\left(-1\right)+\frac{3}{7}\)

\(=0+\frac{3}{7}=\frac{3}{7}\)

-5

bài này dễ tự giải mik làm rồi

http://dethi.violet.vn/present/show/entry_id/11735005

bạn vao link nay nha