{[14:(-12)]+7}:2021
a) \(14.\)\(7^{2021}=35.7^{2021}-3.49^x\)
Tính tổng đại số sau:
a)A=6-13-14+15+16-17-18+19+20-...-2021-2022+2023+2024
b)B=7-9-10+11+12-13-14+15+16-...-2017-2018+2019+2020
Tính tổng đại số sau:
a)A=6-13-14+15+16-17-18+19+20-...-2021-2022+2023+2024
b)B=7-9-10+11+12-13-14+15+16-...-2017-2018+2019+2020
T^T
2022x-2021 + 3 =( 7-5 )2 14* ( x+1) + ( x+2) +...+( x+30 ) = 795
2022x-2021 + 3 =( 7-5 )2 14* ( x+1) + ( x+2) +...+( x+30 ) = 795
2022x-2021 + 3 =( 7-5 )2 14* )( x+1) + ( x+2) +...+( x+30 ) = 795
*Thực hiện
1/ (\(\dfrac{2021}{2020}\)+\(\dfrac{2020}{2021}\)) x (\(\dfrac{1}{2}\)-\(\dfrac{1}{3}\)-\(\dfrac{1}{6}\))
2/ (\(\dfrac{7}{19}\)-\(\dfrac{5}{12}\)):\(\dfrac{-5}{8}\)-(\(\dfrac{7}{19}\)-\(\dfrac{29}{12}\)):\(\dfrac{5}{8}\)
3/ \(\dfrac{-5}{6}\)x\(\dfrac{7}{24}\)-\(\dfrac{5}{6}\)x\(\dfrac{14}{24}\)-\(\dfrac{5}{6}\)x\(\dfrac{3}{24}\)
cho H=1+7+7^2+7^3+7^12+7^13+7^2020+7^2021 chứng mình H chia hết cho 8