Cho đa thức R(x) = x2 – 2x. Tính giá trị biểu thức S = 1 r(3) 1 r(4) 1 r(2022) 1 r(2023)

R(x) = x² – 2x = x(x – 2)

R(3) = 3² – 2.3 = 3(3 – 2) = 1.3

R(4) = 2.4

R(5) = 3.5

….

R(2023) = 2021.2023

S=1R3+1R4+...+1R2022+1R2023S=11.3+13.5+...+12021.2023+12.4+...12020.2022S=12.21.3+...+22021.2023+22.4+...22020.2022S=12.1−13+13−15+...+12021−12023+12−14+...12020−12022S=12.20222023+5051011S≈0,7496