=(2*2)/(1*3)*(3*3)/(2*4)*(4*4)/(3*5)*(5*5)/(4*6)*******(99*99)/(98*100)
=(2方*3方****99方)/(1*2*3方****99*100)
=(2方*99方)/(1*2*99*100)
=2*99/100
=1.98
=(2*2)/(1*3)*(3*3)/(2*4)*(4*4)/(3*5)*(5*5)/(4*6)*******(99*99)/(98*100)
=(2方*3方****99方)/(1*2*3方****99*100)
=(2方*99方)/(1*2*99*100)
=2*99/100
=1.98