Tính B=$\frac{2.1+1}{\left[1\left(1+1\right)\right]^2}+\frac{2.2+1}{\left[2\left(2+1\right)\right]^2}+\frac{2.3+1}{\left[3\left(3+1\right)\right]^2}+......+ $\frac{2.99+1}{[99(99+1)]^{2}}$
Loga
Sinh Học lớp 12
