Question

a) x + 3y= 6
2x + y = -3

b) 4x - 2y = 8
- x + y = 6

c) x - y = 12
4x + y = 3

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Answer 1

Explicação passo-a-passo:

a)

x + 3y = 6

2x + y = -3

x = 6 - 3y

2 . (6 - 3y) + y = -3

12 - 6y + y = - 3

12 - 5y = - 3

12 + 3 = 5y

15 = 5y

15/ 5 = y

3 = y

2x + 3 = - 3

2x = -3 - 3

2x = - 6

x= -6/2

x= -3 s = ( -3 , 3)

b) 4x - 2y = 8

-x + y = 6 (2)

-2x + 2y = 12

4x + (- 2x) = 20

2x = 20

x = 20/ 2 = 10

4. 10 - 2y = 8

40 - 2y = 8

40 - 8 = 2y

32 = 2y

32/2 = y

y = 16 s = (10, 16)

c)

x - y = 12

4x + y = 3

5x = 15

x = 15/5 = 3

3 - y = 12

-y = 12 - 3

-y = 9

y= -9

s= (3,-9)