yagolds1 18/10/2013 2x + y = 7 x - y = 23x = 9x = 9 : 3x = 3Valor de y: 2 . 3 + y = 76 + y = 7y = 7 - 6y = 1resposta: x = 3, y = 1b) 5x + y = - 3 - 5x + 10 y = 80 11y = 77 y = 77 : 11 y = 7Valor de x:5x + 7 = - 35x = - 3 - 75x = - 10x = - 10 : 5x = - 2resposta: x = - 2, y = 7c) x + y = 1138 x - y = - 5402x = 598x = 598 : 2x = 299Valor de y:299 + y = 1138y = 1138 - 299y = 839resposta: x = 299, y = 839
yagolds1
2x + y = 7
x - y = 2
3x = 9
x = 9 : 3
x = 3
Valor de y:
2 . 3 + y = 7
6 + y = 7
y = 7 - 6
y = 1
resposta: x = 3, y = 1
b) 5x + y = - 3
- 5x + 10 y = 80
11y = 77
y = 77 : 11
y = 7
Valor de x:
5x + 7 = - 3
5x = - 3 - 7
5x = - 10
x = - 10 : 5
x = - 2
resposta: x = - 2, y = 7
c) x + y = 1138
x - y = - 540
2x = 598
x = 598 : 2
x = 299
Valor de y:
299 + y = 1138
y = 1138 - 299
y = 839
resposta: x = 299, y = 839