Question

lam cau 4 cau 1 , 2 ,3 giup toi

Answer 1

Câu I:

1:

a: \(=\dfrac{4}{27}:\dfrac{1-10}{15}+\dfrac{4}{9}:\dfrac{2-5}{22}\)

\(=\dfrac{4}{27}\cdot\dfrac{15}{-9}+\dfrac{4}{9}\cdot\dfrac{22}{-3}\)

\(=\dfrac{-60}{243}-\dfrac{88}{27}=\dfrac{-852}{243}=-\dfrac{284}{81}\)

b: \(=\dfrac{2^{24}\cdot3^{15}\cdot5-2^{26}\cdot3^{15}}{19\cdot2^{24}\cdot3^{14}-2^{25}\cdot3^{16}}\)

\(=\dfrac{2^{24}\cdot3^{15}\left(5-2^2\right)}{2^{24}\cdot3^{14}\left(19-2\cdot3^2\right)}=3\)

2: N=1+3+3^2+...+3^2022

=>3N=3+3^2+...+3^2023

=>2N=3^2023-1

=>\(N=\dfrac{3^{2023}-1}{2}\)

\(M=\dfrac{3^{2023}-1-3^{2023}}{2}=\dfrac{-1}{2}\)