(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)+(1+2^31)=(1-1/2)(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)/(1-1/2)+1+1/2^31
=(1-1/2²)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)/(1-1/2)+1+1/2^31
=(1-1/2^4)(1+1/2^4)(1+1/2^8)(1+1/2^16)/(1-1/2)+1+1/2^31
=(1-1/2^8)(1+1/2^8)(1+1/2^16)/(1-1/2)+1+1/2^31
=(1-1/2^16)(1+1/2^16)×2+1+1/2^31
=2-1/2^31+1+1/2^31
=3