(1-1/2)x(1-1/3)x(1-1/44)x(1-1/5)x(1-1/6)
=1(-1/2-1/3-1/4-1/5-1/6)
=-1/2-1/3-1/4-1/5-1/6
=-(1/2+1/3+1/4+1/5+1/6)
=-( (1/2+1/3+1/6)+(1/4+1/5))
=-((3/6+2/6+1/6)+(5/20+4/20))
= -(1+9/20)
=-29/20
1/2*2/3*3/4*4/5*5/6
rút gọn =1/6
các bạn k đúng hộ mình nhé