Chứng tỏ rằng: D = 12/^2 + 1/3^2 + 1/4^2 +...........+ 1/10^2 < 1

1.Chứng to rằng: D=$\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...........+\frac{1}{{10}^2}<1$
2.Tìm x biết: $\frac{1}{5\times 8}+\frac{1}{8\times 11}+\frac{1}{11\times 14}+............+\frac{1}{x(x+3)}=\frac{101}{1504}$