1+2+3-4-5+1+1+2+3=
1+2+3-4-5+1+1+2+3=
1 2 3 4 5=1
(1)1+2+1=4;1+2+3+2+1=_______;1+2+3+4+3+2+1=_______;1+2+3+4+5
1+2=3 4+5=?
1+1=?还有1+2+3+4+5=?
(2*3*4*5)*(1/2+1/3+1/4+1/5)=
(1+1/2+1/3+1/4)×(1/2+1+1/3+1/4+1/5)×(1/2+1/3+1/4) =简便方法
1/1×2+1/1-1/2:;1/2×4=1/2×(1/2-1/4);1/58×=1/3(×1/5-1/8)
1 2 3 4 5 =200
1+2+3+4+5+.10000=
1+2+3+4+5+6=
1+2-3+4-5+6=