Odpowiedzi

2009-12-06T15:47:16+01:00
4(2x+3)-2(4y-1)=30
4(5x+1)-3(y-3)=36

8x+12-8y+2 =30 /:2
20x+13 - 3y = 36

4x+7-4y = 15
20x-3y = 23

4x = 8+4y /:4
20x-3y = 23

x = 2+y
20(2+y) - 3y =23

x = 2+y
40+20y - 3y = 23

x = 2+y
17y = -17

x = 2+y
y = -17/17 = -1

x = 1
y = -1