Răspuns:
Explicație pas cu pas:
1-x=1/7 => x=1-1/7 => x=(7-1)/7 => x=6/7
1-x=4/9 => x=1-4/9 => x= (9-4)/9 => x=5/9
x+2/3=1 => x=1-2/3 => x=(3-2)/3 => x=1/3
x+3/8=1 => x=1-3/8 => x=(8-3)/8 => x=5/8
