Question

[Hà ngọc minh]

 

Answer 1

[Nguyễn Thị Thương Hoài]

Câu 7:

b; \(\dfrac{11}{2}\) - 3 = \(\dfrac{11}{2}\) - \(\dfrac{6}{2}\) = \(\dfrac{5}{2}\)

c; \(\dfrac{2}{3}\) x \(\dfrac{3}{4}\) = \(\dfrac{1}{2}\)

d; \(\dfrac{4}{15}\) : \(\dfrac{2}{5}\) = \(\dfrac{4}{15}\) x \(\dfrac{5}{2}\) = \(\dfrac{2}{3}\)

Answer 2

[Nguyễn Thị Thương Hoài]

Bài 9:

a; \(\dfrac{21}{25}\) x \(\dfrac{2}{5}\) + \(\dfrac{21}{25}\) x \(\dfrac{3}{5}\)

= \(\dfrac{21}{25}\) x (\(\dfrac{2}{5}\) + \(\dfrac{3}{5}\))

= \(\dfrac{21}{25}\) x 1

= \(\dfrac{21}{25}\)