Bx3=1x3/1x2x3x4+1x3/2x3x4x5+...+1x3/97x98x99x100
Bx3=3/1x2x3x4+3/2x3x4x5+...+3/97x98x99x100
Bx3=1/1x2x3-1/2x3x4+1/2x3x4-1/3x4x5+...+1/97x98x99-1/98x99x100
BX3=1/1x2x3-1/98x99x100
BX3=1/6-1/970200
Bx3=161700/970200-1/970200
Bx3=161399/970200
B=161699/970200:3
B=161699/970200x1/3
B=161699/2910600