Respostas

2013-11-27T14:06:33-02:00
7-) x = 116 
10-)a-) x = -y + 1
4 (-y +1) + 7y = 10
-4y + 4 + 7y = 10
3y = 6
y= 2

x + 2 = 1
x = -1

B-)x= 2y + 2
3 (2y + 2) + y =13
6y + 6 + y = 13
7y = 7
y= 1 

x-2.1=2
x= 4

c-) y= -2x +4

3x -(-2x +4) = 1
3x + 2x = 4+1 
5x = 5
x= 1

y= -2.1 + 4
y= -2 +4
y= 2

D-)x = y+1
2 (y+1) +y = 5
2y + 2 +y = 5
3y = 3
y = 1

x= 1+1
x= 2

e-) x= -y+4
3 (-y+4) + 2y = 9
-3y +12 + 2y = 9
-y = -3
y = 3

X= -3 + 4
X= 1
2 4 2