Câu hỏi của Viet Anh Ho

Question

B = 1/2x3 + 1/3x4 + 1/4x5 * ... x + 1/ 2022x2023

Nguyễn Đức Trí · Accepted Answer

$B=\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}+...+\dfrac{1}{2022.2023}$

$B=\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+...+\dfrac{1}{2022}-\dfrac{1}{2023}$

$B=\dfrac{1}{2}-\dfrac{1}{2023}=\dfrac{2021}{4046}$Câu trả lời: $B=\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}+...+\dfrac{1}{2022.2023}$

$B=\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+...+\dfrac{1}{2022}-\dfrac{1}{2023}$

$B=\dfrac{1}{2}-\dfrac{1}{2023}=\dfrac{2021}{4046}$