i used to walked to school when i was a student

I used to walk to school when I was a student

Sửa đề: \(A=1-\dfrac{3}{4}+\left(\dfrac{3}{4}\right)^2-\left(\dfrac{3}{4}\right)^3+...-\left(\dfrac{3}{4}\right)^{2019}\)

\(\Leftrightarrow A\cdot\dfrac{3}{4}=\dfrac{3}{4}-\left(\dfrac{3}{4}\right)^2+...-\left(\dfrac{3}{4}\right)^{2020}\)

=>\(A\cdot\left(\dfrac{3}{4}+1\right)=\dfrac{3}{4}-\left(\dfrac{3}{4}\right)^2+...-\left(\dfrac{3}{4}\right)^{2020}+1-\dfrac{3}{4}+...-\left(\dfrac{3}{4}\right)^{2019}\)

=>\(A\cdot\dfrac{7}{4}=\dfrac{-3^{2020}}{4^{2020}}+1=\dfrac{4^{2020}-3^{2020}}{4^{2020}}\)

=>\(A=\dfrac{4^{2020}-3^{2020}}{4^{2019}\cdot7}\) không phải là số nguyên

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I am interested in watching this film

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c

C.Festival

--5²²-{-222-[-122-(100-5²²)+2024]}

--5²²-{-222-[-122-95²²+2024]}

--5²²-{-222+ 122-95²²+2024}

--5²²+ 2029²²

2034²²

=-5^22+222-112-100+5^22+2022

=(-5^22+5^22)+(222-112-100)+2022

=0+0+2022

=2022

\(\dfrac{4}{3}+\dfrac{-11}{31}+\dfrac{3}{10}-\dfrac{20}{31}-\dfrac{2}{5}\)

\(=\dfrac{4}{3}+\left(\dfrac{3}{10}-\dfrac{2}{5}\right)+\left(-\dfrac{11}{31}-\dfrac{20}{31}\right)\)

\(=\dfrac{4}{3}-1-\dfrac{1}{10}=\dfrac{1}{3}-\dfrac{1}{10}=\dfrac{7}{30}\)

bài 2:

a: \(A=\dfrac{1}{5}+\dfrac{1}{5^2}+...+\dfrac{1}{5^{2014}}\)

=>\(5A=1+\dfrac{1}{5}+...+\dfrac{1}{5^{2013}}\)

=>\(5A-A=1+\dfrac{1}{5}+...+\dfrac{1}{5^{2013}}-\dfrac{1}{5}-\dfrac{1}{5^2}-...-\dfrac{1}{5^{2024}}\)

=>\(4A=1-\dfrac{1}{5^{2024}}\)

=>\(A=\dfrac{1}{4}-\dfrac{1}{4\cdot5^{2024}}< \dfrac{1}{4}\)