Question

usando método da adição

x + y = 6
x - y = 2
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x + y = 4
x - y = 8
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x - y = 2
2x + y = 4
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x + y = 11
x - y = 3

Answer 1

a)
x=2+y

2+y+y=6
2y=4
y=2

x-2=3
x=1


b)
x=y+8

y+8+y=4
2y=-4
y=-2

x+2=2
x=0

c)
x=2+y

4y+2y+y=4
5y=4
y=4/5

x-4/5=2
x=28/10


d)
x=3+y
3+y+y=11
2y=8
y=4

x+4=11
x=7