Question

[Nguyễn Vân Ly]

tính giá trị biểu thức sau:

A = 7/4 . ( 3333/1212 + 3333/2020 + 3333/3030 + 3333/4242)

Answer 1

[TXT Channel Funfun]

\(A=\frac{7}{4}.\left(\frac{3333}{1212}+\frac{3333}{2020}+\frac{3333}{3030}+\frac{3333}{4242}\right)\)

\(A=\frac{7}{4}.\left(\frac{33}{12}+\frac{33}{20}+\frac{33}{30}+\frac{33}{42}\right)\)

\(A=\frac{7}{4}.33.\left(\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)

\(A=\frac{231}{4}.\left(\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\right)\)

\(A=\frac{231}{4}.\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)

\(A=\frac{231}{4}.\left(\frac{1}{3}-\frac{1}{7}\right)\)

\(A=\frac{231}{4}.\frac{4}{21}\)
\(A=11\)

Answer 2

[hồ quỳnh anh]

A = 11 nha !