a. 2*3 + 3*y = -6
6 + 3y = -6
3y = -6-6
3y = -12
y = -4
b. 4x-(2x-1) = 12
4x-2x+1 = 12
2x+1 = 12
2x = 11
x = 11/2
c. 2x = 8-y ⇒ x = (8-y)/2
2(8-y)/2+3y = 0
8-y+3y = 0
2y = -8
y = -4
deci x = (8+4)/2
x = 12/2
x = 6
d. 2x +3y = 5
4x - 3y = -4
---------------- (+) aplic metoda reducerii
6x / = 1
x = 1/6
2*1/6 + 3y = 5
3+3y = 5
3y = 2
y = 2/3
