Răspuns:
Explicație pas cu pas:
2x + 3y = 9 (x 4)
5x - 4y = 11 (x 3)
________
8x + 12y = 36
15x -12y = 33
adunam ecuatiile
8x + 15x = 36 + 33
23x = 69
x = 69 : 23 = 3
y = (9 - 2*3) : 3 = (9 - 6) : 3 = 3 : 3 = 1
2x+3y=9| •4. 8x+12y=36
5x-4y=11| •3 => 15x-12y=33
----------------
23x / =69
x= 69÷23 => x=3
2×3+3y=9 ( am inlocuit)
6+3y=9
3y=9-6
3y=3
y=1
