Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
= 154 . 235 + 154 . (-35)
= 154 . [ 235 + (-35)]
= 154 . 200
= 30800
\(1-\left(x-1\right):3=\dfrac{2}{3}\)
\(\Rightarrow\left(x-1\right):3=1-\dfrac{2}{3}\)
\(\Rightarrow\left(x-1\right):3=\dfrac{1}{3}\)
\(\Rightarrow x-1=\dfrac{1}{3}.3\)
\(\Rightarrow x-1=1\)
\(\Rightarrow x=2\)
c)\(\left(1+\dfrac{1}{2}\right)\left(1+\dfrac{1}{3}\right)\left(1+\dfrac{1}{4}\right)....\left(1+\dfrac{1}{2020}\right)\left(1+\dfrac{1}{2021}\right)\)
\(=\left(\dfrac{1.2}{1.2}+\dfrac{1}{2}\right)\left(\dfrac{1.3}{1.3}+\dfrac{1}{3}\right)...\left(\dfrac{1.2021}{1.2021}+\dfrac{1}{2021}\right)\)
\(=\dfrac{3}{1.2}\cdot\dfrac{4}{1.3}\cdot\cdot\cdot\cdot\dfrac{2022}{1.2021}\)
\(=\dfrac{3.4.5...2022}{\left(1.1.1....1\right)\left(2.3.4...2021\right)}\)
\(=\)\(\dfrac{3.4.5...2022}{2.3.4...2021}\)
\(=\dfrac{2022}{2}=1011\)
\(d\))\(\left(1-\dfrac{1}{2}\right)\left(1-\dfrac{1}{3}\right)....\left(1-\dfrac{1}{199}\right)\left(1-\dfrac{1}{200}\right)\)
\(=\left(\dfrac{2}{1.2}-\dfrac{1}{1.2}\right)\left(\dfrac{3}{1.3}-\dfrac{1}{1.3}\right)....\left(\dfrac{200}{1.200}-\dfrac{1}{1.200}\right)\)
\(=\dfrac{1.2.3....199}{\left(1.1.1....1\right).\left(2.3.4....200\right)}\)
\(=\dfrac{1.2.3...199}{2.3.4...200}\)
Nếu mik làm sai mong bạn thông cảm
Câu 1:
a; \(\dfrac{-9}{4}\) < 0; \(\dfrac{1}{3}\) > o
\(\dfrac{-9}{4}\) < \(\dfrac{1}{3}\)
b; \(\dfrac{-8}{3}\) < - 1
\(\dfrac{4}{-7}\) > - 1
Vậy \(\dfrac{-8}{3}\) < \(\dfrac{4}{-7}\)
c; \(\dfrac{9}{-5}\) < - 1
\(\dfrac{7}{-10}\) > - 1
Vậy \(\dfrac{9}{-5}\) < \(\dfrac{7}{-10}\)
Câu 2:
a; Viết các phân số theo thứ tự tăng dần
\(\dfrac{-1}{2}\); \(\dfrac{2}{7}\); \(\dfrac{2}{5}\)
b; \(\dfrac{-11}{4}\); \(\dfrac{-7}{3}\); \(\dfrac{12}{5}\)