Question

S=\(\dfrac{3}{1.4}+\dfrac{3}{4.7}+...+\dfrac{3}{100.103}\)

Hãy tính tổng S

Các bạn giúp mk nha!!!!

Answer 1

\(S=\dfrac{3}{1.4}+\dfrac{3}{4.7}+........+\dfrac{3}{100.103}\)

\(\Leftrightarrow S=1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+.........+\dfrac{1}{100}-\dfrac{1}{103}\)

\(\Leftrightarrow S=1-\dfrac{1}{103}=\dfrac{102}{103}\)

Answer 2

S=\(\dfrac{3}{1.4}+\dfrac{3}{4.7}+...+\dfrac{3}{100.103}\)

S=\(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+...+\dfrac{1}{100}-\dfrac{1}{103}\)

S=\(1-\dfrac{1}{103}=\dfrac{102}{103}\)

Answer 3

\(S=1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+...+\dfrac{1}{100}-\dfrac{1}{103}\)

\(S=1-\dfrac{1}{103}\)

\(S=\dfrac{102}{103}\)

~ chúc bn hk tốt ~

Answer 4

S=\(\dfrac{3}{1.4}+\dfrac{3}{4.7}+...+\dfrac{3}{100.103}\)

=1-\(\dfrac{1}{4}\)+\(\dfrac{1}{4}\)-\(\dfrac{1}{7}\)+...+\(\dfrac{1}{100}\)-\(\dfrac{1}{103}\)

= 1-\(\dfrac{1}{103}\)=\(\dfrac{103}{103}\)-\(\dfrac{1}{103}\)=\(\dfrac{102}{103}\)

Vậy S= \(\dfrac{102}{103}\)

Answer 5

S = \(\dfrac{3}{1.4}+\dfrac{3}{4.7}+....+\dfrac{3}{100.103}\)

S = \(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+....+\dfrac{1}{100}-\dfrac{1}{103}\)

S = \(1-\dfrac{1}{103}\)

S = \(\dfrac{102}{103}\)