Răspunsuri

2014-06-13T15:57:16+03:00
X-cat costa un pix
y-cat costa un caiet

3x+2y=38

5x-20=y

3x+2(5x-20)=38

3x+10x-40=38
13x=38+40
13x=78
x=6

y=6*5-20
y=30-20
y=10
1 5 1
2014-06-13T16:42:43+03:00

x-pretul unui pix

y-pretul unui caiet

3x+2y=38

5x=20+y

5x-y=20 |*2


3x+2y=38

10x-2y=40

13x=78

x=78/13

x=6

5*6=20+y

y=30-20

y=10


1 5 1