Respostas

2013-10-16T18:12:52-03:00
b)9.(-y+2) = 2+5.(Y-1) 
-9y +18 = 2+ 5y -5
-9y -5y = -3 -18
-14y =-21(-1)
14y=21
y=21/14
C)3y-15 = 2y-8
3y -2y =-8 +15
y =7
2013-10-16T18:41:12-03:00
B)9.(-y+2) = 2+5.(Y-1)  = -9y - 18  = 2 + 5y -5= -9y -5y = 2 -5 +9
= -14y = +6
= y = -    6     =        x =   3            
             14                       7
 C)3y-15 = 2y-83y -2y = 15 -8
y = 7