Question

urgente!!! valendo 20 pts
resolva usando o metodo da adição

a)
2x+y=5
-8x+y=0

b)
2x+y=9
x+3y=2

c)
-3x+y=0
x+4y=26

d)
2x-3y=2
5x-7y=6

e)
4x-2y=2
2x+3y=-7

Answer 1

Vamos lá

a)

2x+y=5

-8x+y=0

10x = 5

x = 1/2

1 + y = 5

y = 4

S = (1/2, 4)

b)

2x+y=9

x+3y=2

2x + 6y = 4

5y = -5

y = -1

2x - 1 = 9

2x =  10

x = 5

S(5, -1)

c)

-3x+y=0

x+4y=26

3x + 12y = 78

13y = 78

y = 6

x  + 24 = 26

x = 2

S = (2, 6)

d)

2x-3y=2

5x-7y=6

10x - 15y = 10

10x - 14y = 12

y = 2

2x - 6 = 2

2x = 8

x = 4

e)

4x-2y=2

2x+3y=-7

12x - 6y = 6

4x + 6y = -14

16x = -8

x = -1/2

-1 + 3y = -7

3y = -6

y = -2

S = (-1/2, -2)