Odpowiedzi

2010-01-12T22:20:14+01:00
2010-01-12T22:23:25+01:00
4x+4y=1200
2x+6y=920 ||×(-2)

4x+4y=1200
-4x-12y=-1840 //dodajemy stronami

-8y=-640 ||÷(-8)
y=80 => 2x+480=920, czyli 2x=440, x=220
2 3 2
2010-01-12T22:56:11+01:00
4x + 4y = 1200
2x + 6y = 920 / * (-2)

4x + 4y = 1200
- 4x -12y = - 1840

- 8y = -640 /:(-8)
y = 80

2x + 6y = 920
2x + 6 * 80 = 920
2x = 920 -480
2x = 440 /: 2
x = 220

Odp. X = 220, y = 80