«
  
»
Resolva as seguintes Equações :
A) x-2y =7 B) x+y =1 C) x+3y =1 D) x+y =14
3x+y =35 x-2y =1 5x+3y =17 2x-y =5


RESOLVENDO

A)
x-2y=7 x=7+2y
3x+y=35
3(7+2y)+y=35
21+6y+y=35
21+7y=35
7y=35-21
7y=14
y=14/7
y=2
x=7+2y
x=7+2.2
x=7+4
x=11
b)
x+y=1 x=1-y
x-2y=1
1-y-2y=1
1-3y=1
-3y=1-1 (-1)
3y=-1+1
3y=0
x=1-y
x=1-0
x=1
c)
x+3y=1
5x+3y=17 x=1-3y
5(1-3y)+3y=17
5-15y+3y=17
5-12y=17
-12y=17-5
-12y=12 (-1)
12y=-12
y=-12/12
y=-1
x=1-3y
x=1-3.1
x=1-3
x=-2
d)
x+y=14 x=14-y
2x-y=5
2(14-y)-y=5
28-2y-y=5
28-3y=5
-3y=5-28
-3y=-23 (-1)
3y=23
y=23/3
x=14-23/3
x=42/3-23/3
x=19/3



TAREFAS SIMILARES: