Đáp án:
$\rm M=\dfrac{3}{13}$
Giải thích các bước giải:
$\rm M=\dfrac{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{11}}{\dfrac{13}{4}-\dfrac{13}{5}+\dfrac{13}{7}+\dfrac{13}{11}}$
`=>`$\rm M=\dfrac{3\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{11}\right)}{13\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{11}\right)}$
`=>`$\rm M=\dfrac{3}{13}$
Vậy $\rm M=\dfrac{3}{13}$.
