Rút gọn biểu thức: A=2^2/1.3.3^2/2.4.4^2/3.5.5^2/4.6.....99^2/98.100
Tính hợp lí
A=2^2/1.3.3^2/2.4+4^2/3.5. ... .999^2/998.1000
B=22/1.2.32/2.4.42/3.5...502/49.51
tính tổng S=2/1.3+2/3.5+2/5.7+2/7.9+2/9.11
Tính giá trị biểu thức:
\(B=\frac{2^2}{1.3}.\frac{3^2}{2.4}.\frac{4^2}{3.5}...\frac{10^2}{9.11}\)
A= 1.1 + 2.2 +3.3 + 4.4 + ... +20.20
B= 1.2.2 + 2.3.3 + 3.4.4 + 19.20.20
C= 1.2 +3.4 + 5.6 + ... + 19.20
tính
a) 2/3.5+2/5.7+2/7.9+2/9.11+2/11.13
b) 1/1.2.3.4+1/2.3.4.5+1/3.4.5.6+1/27.28.29.30
Tính:
a) M=2/3.5+2/5.7+2/7.9+...+2/97.99
b) N=3/5.7+3/7.9+3/9.11+...+3/197.199
TÍNH
Q = \(\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+\frac{2}{9.11}\)