Ta có M= 3*(1/5+1/7-1/11)

               4*(1/5+1/7-1/11)

Nên M=3/4

Ta có:3/5+3/7-3/11=3.(1/5+1/7-1/11)

4/5+4/7-4/11=4.(1/5+1/7-1/11)

=>M=[3.(1/5+1/7-1/11)]/[4.(1/5+1/7-1/11)]=3/4

M = \(\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}=\frac{3\left(\frac{1}{5}+\frac{3}{7}-\frac{3}{11}\right)}{4\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}=\frac{3}{4}\)

\(\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}=\frac{3 \left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}{4\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}=\frac{3}{4}\)

=3[1/5+1/7-1/11]

-----------------------     =3/4

  4[1/5+1/7-1/11]

\(\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}=\frac{3\cdot\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}{4\cdot\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}=\frac{3}{4}\)

@_@

Học tốt ^^

đánh sai đề rồi

a = 241/385

b = 53/72

c = 571/385

d = 533/231

\(=\dfrac{3\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{11}\right)}{13\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{17}+\dfrac{1}{11}\right)}=\dfrac{3}{13}\)

\(\dfrac{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{11}}{\dfrac{13}{4}-\dfrac{13}{5}+\dfrac{13}{7}+\dfrac{13}{11}}\)

\(=\dfrac{3\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{11}\right)}{13\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{11}\right)}\)

\(=\dfrac{3}{13}\)

trên 4 phần năm là sao z 

có thể chụp lại đc ko ??
 

4/10 chia 3/5 nhân 1/2 trả lời