Question

[Minh Hà Nguyễn]

{\(\frac{2}{15}+\frac{5}{3}-\frac{3}{5}\)} : {\(4\frac{2}{3}-2\frac{1}{5}\)}

{\(\frac{2}{1x3}+\frac{2}{3x5}.\).......\(+\frac{2}{19x21}\)} x {\(\frac{2}{21}x\frac{3}{8}-\frac{5}{2}:70\)}

Answer 1

[Đỗ Quốc Hoàng]

{9/5-3/5} : {15/3-11/5}

6/5:14/5

6/5x5/14=3/7

Câu 2:

{2/1x3+2/3x5+...+2/19x21} x{1/28-5/2x1/70}

{2/1x3+2/3x5+...+2/19x21} x{1/28-1/28}

{2/1x3+2/3x5+...+2/19x21} x0=0