Question

11 cai si 7 vaci mananca intro zi 130 kg nutret iar 15 cai si 21 vaci mananca intro zi 246 kg nutret cat mananca o vaca dar un cal intro zi

Answer 1

notam cu x =cant de nutret  /cal /zi
notam cu y =cant de nutret /vaca/zi
{11x+  7y=130
{15x+21y=246 |÷3

{11x+  7y=130 (-)
{ 5x +  7y= 82
______________
6x     /     =48
x=48/6
x=8 kg/cal/zi
11*8+7y=130
88+7y=130
7y=130-88
7y=42
 y=42/7
y=6 kg/vaca/zi