Question

resolva os sistemas pelo método da adição

Answer 1

b)x+2y=7
x-2y= -5
___________+
2x =2
x=2/2
x=1

x+2y=7
1+2y=7
2y=7-1
y=6/2
y=3






a) x-y=5
x+y=7
_______+
2x=12
x=12/2
x=6

x-y=5
6-y=5
6-5=y
y=1

c)2x-y=0
x+y=15
________+
3x = 15
x=15/3
x=5

x+y=15
5+y=15
y=15-5
y=10

d)x-y=6
x+y=-7
______+
2x = - 1
x= -1/2

x-y=6
-1/2-y=6
-y= 6 + 1/2
-y= 12+1/2
-y= 13/2
y= -13/2