cóa tui nek!

b)

\(\dfrac{7}{2}+\dfrac{4}{5}+\dfrac{3}{6}\\=\dfrac{7}{2}+\dfrac{4}{5}+\dfrac{1}{2}\\= \left(\dfrac{7}{2}+\dfrac{1}{2}\right)+\dfrac{4}{5}\\ =4+\dfrac{4}{5}\\=\dfrac{20}{5}+\dfrac{4}{5}\\ =\dfrac{24}{5} \)

mk lm rùi đó! nhớ tick mk nha! Chúc bn hk tốt!