Răspuns :
a + b = 17/12
a - b = 1/12
__________ "+"
2a / = 18/12
2a=3/2
a=3/2 : 2
a=3/2 × 1/2
a=3/4
3/4 + b = 17/12
b=17/12 - 3/4
b=(17-9)/12
b=8/12
b=2/3
a - b = 1/12
__________ "+"
2a / = 18/12
2a=3/2
a=3/2 : 2
a=3/2 × 1/2
a=3/4
3/4 + b = 17/12
b=17/12 - 3/4
b=(17-9)/12
b=8/12
b=2/3
x+y=17/12
x-y= 1/12 si le adunam
-------------------
2x=18/12=3/2
x=3/4
y=x-1/12=9/12-1/12=8/12=2/3
x-y= 1/12 si le adunam
-------------------
2x=18/12=3/2
x=3/4
y=x-1/12=9/12-1/12=8/12=2/3