\(a)x-5,01=7,02-2.1,5.\)
\(\Leftrightarrow x-5,01=4,02.\\ \Leftrightarrow x=9,03.\)
\(b)x-\dfrac{3}{10}=\dfrac{7}{15}.\dfrac{3}{5}.\\ \Leftrightarrow x-\dfrac{3}{10}=\dfrac{-2}{15}.\\ \Leftrightarrow x=\dfrac{1}{6}.\)
Đăng tách ra bạn nhé
Câu 6
Ta có \(\dfrac{1}{2^2}< \dfrac{1}{1.2};\dfrac{1}{3^2}< \dfrac{1}{2.3};...;\dfrac{1}{2022^2}< \dfrac{1}{2021.2022}\)
Cộng vế với vế
\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+...+\dfrac{1}{2022^2}< \dfrac{1}{1.2}+\dfrac{1}{2.3}+...+\dfrac{1}{2021.2022}=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{2021}-\dfrac{1}{2022}=\dfrac{2021}{2022}< 1\)
Vậy ta có đpcm
ko làm đề kiểm tra đc bạn nhé
