Question

\(\left(\frac{242}{363}+\frac{1616}{2121}\right)=\frac{2}{7}\cdot\frac{2015}{A}\)Tìm A biết: 

Answer 1

\(\frac{242}{363}+\frac{1616}{2121}=\frac{2}{7}.\frac{2015}{A}\)

\(\frac{11.11.2}{11.11.3}+\frac{101.16}{101.21}=\frac{2}{7}.\frac{2015}{A}\)

\(\frac{2}{3}+\frac{16}{21}=\frac{2}{7}.\frac{2015}{A}\)

\(\Rightarrow\frac{2}{7}.\frac{2015}{A}=\frac{10}{7}\)

\(\frac{2015}{A}=\frac{10}{7}:\frac{2}{7}\)

\(\frac{2015}{A}=5\)

\(A=2015:5\)

\(A=403\)

Answer 2

\(\left(\frac{242}{363}+\frac{1616}{2121}\right)=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow\left(\frac{2}{3}+\frac{16}{21}\right)=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow\frac{10}{7}=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow5=\frac{2015}{A}\)

\(\Leftrightarrow A=403\)

Answer 3

10/7 = 2/7 . 2015/A

2015/A = 10/7 / 2/7 = 5

2015/A = 5/1

A = 2015 / 5 = 403