Răspuns:
(1+1/2+1/3+1/4-1/2:0,5)•12/13=1
(1+1/2+1/3+1/4-1/2:5/10)×12/13=1
(1+1/2+1/3+1/4-1/2×10/5)•12/13=1
(1+1/2+1/3+1/4-1/2×2)•12/13=1
(1+1/2+1/3+1/4-1)•12/13=1
(6/12+4/12+3/12)×12/13=1
13/12×12/13=1
1=1
Adevarat
Explicație pas cu pas:
