tính nhanh (1x98+2x97+3x96+...+98x1)/1x2+2x3+3x4+4x5+5x6+...+98x99
tính tổng sau
B=1x98+2x97+3x96+..............+98x1 / 1x2+2x3+3x4+.................+98x99
Tính
\(\frac{1x98+2x97+3x96+............+98x1}{1x2+2x3+3x4+..........+98x99}\)
1x98+2x97+3x96+...+98x1
2x3+3x4+4x5+5x6+...+98x99
giúp mình nha
1x2+2x3+3x4+...+98x99+99x100 = ?
9/1x2+9/2x3+9/3x4+.................+9/98x99+9/99x100
TÍNH
A= 9/1x2 + 9/2x3 + 9/3x4 +..........+ 9/98x99 + 9/99x100
Cho B=1+(1+2)+(1+2+3)+...+(1+2+3+...+98)/1x98+2x97+3x96+...98x1 Vậy B= bao nhiêu
Tính giá trị biểu thức:
A=9/1x2 + 9/2x3 + 9/3x4 +...+9/98x99 + 9/99x100