Question

Viết 3 số hữu tỉ xen giữa \(\frac{-1}{3}\) và \(\frac{-1}{4}\)

Answer 1

Áp dụng tính chất \(\frac{a}{b}< \frac{c}{d}\Rightarrow\frac{a+c}{b+d}\)

Ta có \(-\frac{1}{3}< -\frac{1}{4}\Rightarrow-\frac{1}{3}< \frac{\left(-1\right)+\left(-1\right)}{3+4}< -\frac{1}{4}\Rightarrow-\frac{1}{3}< -\frac{2}{7}< -\frac{1}{4}\)

          \(-\frac{1}{3}< -\frac{2}{7}\Rightarrow-\frac{1}{3}< \frac{\left(-1\right)+\left(-2\right)}{3+7}< -\frac{2}{7}\Rightarrow-\frac{1}{3}< -\frac{3}{10}< -\frac{2}{7}\)

          \(-\frac{1}{3}< -\frac{3}{10}\Rightarrow-\frac{1}{3}< \frac{\left(-1\right)+\left(-3\right)}{3+10}< -\frac{3}{10}\Rightarrow-\frac{1}{3}< -\frac{4}{13}< -\frac{3}{10}\)

Vậy \(-\frac{1}{3}< -\frac{4}{13}< -\frac{3}{10}< -\frac{2}{7}< -\frac{1}{4}\)

Answer 2

Gọi số cần tìm là a

Ta có : \(\frac{-1}{3}< a< \frac{-1}{4}\)

\(\frac{-16}{48}< a< \frac{-12}{48}\)

\(\Rightarrow a\in\left\{\frac{-5}{16};\frac{-7}{24};\frac{-13}{48}\right\}\)

Answer 3

\(\frac{-15}{48};\frac{-14}{48};\frac{-13}{48}\)

Answer 4

3 số hữu tỉ là:

\(-\frac{4}{15};-\frac{3}{10};-\frac{19}{60}\)

Answer 5

-1/3 >-11/12>-7/12>-5/6>-1/4

Answer 6

-1/3 < -4/13 < -3/10 < -2/7 < -1/4