Question

有理数得乘法(1+1分之11 +1分之13+1分之17)乘(11分之1+13分之1+17分之1+19分之1)-(1+11

Answer 1

(1+1/11+1/13+1/17)*(1/11+1/13+1/17+1/19)-(1+1/11+1/13+1/17+1/19)*(1/11+1/13+1/19)

=(1+1/11+1/13+1/17)*(1/11+1/13+1/19)+(1+1/11+1/13+1/17)*1/17-(1+1/11+1/13+1/17)*(1/11+1/13+1/19)-1/19*(1/11+1/13+1/19)

=903391 / 14919047