Question

[ 1/12 + 1/20 + 1/30 + 1/42 + ... + 1/9900 ] : x = 1/5

Answer 1

Giúp mình với !!!!!!! One k ^_^

Answer 2

Ta có \(\left(\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+...+\frac{1}{9900}\right):x=\frac{1}{5}\)

\(\left(\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}+\frac{1}{6\times7}+...+\frac{1}{99\times100}\right):x=\frac{1}{5}\)

\(\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{99}-\frac{1}{100}\right):x=\frac{1}{5}\)

\(\left(\frac{1}{3}-\frac{1}{100}\right):x=\frac{1}{5}\)

\(\frac{97}{300}:x=\frac{1}{5}\)

\(x=\frac{97}{300}:\frac{1}{5}\)

\(x=\frac{97}{60}\)

Answer 3

Cảm ơn bạn nhé!!!!