\(\dfrac{1}{2\cdot3}+\dfrac{1}{3\cdot4}+...+\dfrac{1}{99\cdot100}\)
\(=\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{99}-\dfrac{1}{100}\)
\(=\dfrac{1}{2}-\dfrac{1}{100}\)
\(=\dfrac{50}{100}-\dfrac{1}{100}\)
\(=\dfrac{49}{100}\)
A= 1/1x2 + 1/2x3 + 1/3x4 + .........+1/99x100
tính 1/2x3+1/3x4+1/4x5+...1/99x100
Tinh: 1/1x2+1/2x3+1/3x4+...+1/99x100
tinh:
a,1/2x3 +1/3x4 + 1/4x5 +.....+1/99x100
1/2x3 + 1/3x4 + 1/4x5 +...+ 1/99x100
CHÚC CÁC BẠN LÀM TỐT
so sánh A và B biết
A=\(\dfrac{1}{2x3}+\dfrac{1}{3x4}+\dfrac{1}{4x5}+...+\dfrac{1}{99x100}\)
B=\(\dfrac{1}{1x3}+\dfrac{1}{3x5}+\dfrac{1}{5x7}+...+\dfrac{1}{97x99}\)
1x2+2x3+3x4+...+98x99+99x100 = ?
Tinh : 1x2+2x3+3x4+...+99x100
1X2+2X3+3X4+..........+99X100+100X101
