Question

resolva os sistemas lineares abaixo:

a) x - y= 1
2x + y= 5

b) x + 2y= 5
2x - 3y= –4

c) 3x - 4y= 1
x + 3y= 9

d) 3x + y= 9
2x + 3y= 13​

Answer 1

a) x - y= 1

2x + y= 5

adiçao:

3x = 6

x = 3

3 - y = 1

y = 2

S = ( 3, 2 )

b) x + 2y= 5

2x - 3y= –4

2x + 4y = 10

7y = 14

y = 2

x + 4 = 5

x = 1

S = ( 1 , 2 )

c) 3x - 4y= 1

x + 3y= 9

3x + 9y = 27

13y = 26

y = 2

3x - 8 = 1

3x = 9

x = 3

S = ( 3, 2)

d) 3x + y= 9

2x + 3y= 13​

9x + 3y = 27

7x = 14

x = 2

6 + y = 9

y = 9 - 6 = 3

S = ( 2, 3)