Răspuns :
a+b+c+d
------------ = 8
4
c+d
----- = 6
2
a+b+c+d= 8x4= 32
c+d= 12
a+b+12=32
a+b=20
==>
a+b
----- = 10
2
------------ = 8
4
c+d
----- = 6
2
a+b+c+d= 8x4= 32
c+d= 12
a+b+12=32
a+b=20
==>
a+b
----- = 10
2
a+b+c+d/4 =8 ;a+b+c+d=4*8 =32
c+d/2 =6 ; c+d=2*6 =12
a+b + 12 =32
a+b=32-12
a+b =20
c+d/2 =6 ; c+d=2*6 =12
a+b + 12 =32
a+b=32-12
a+b =20