Question

Resolva os seguintes sistemas lineares
A){x+2y=3
{3x-y=-5

B)-x-y=-6
2x-3y=-3

Answer 1

A)

{x+2y=3

{3x-y=-5 (2)

x + 2y = 3

6x - 2y = - 10 (+)

--------------------------

7x = - 7

x = - 7/7

x = - 1

x + 2y = 3

- 1 + 2y = 3

2y = 3 + 1

2y = 4

y = 4/2

y = 2

B)

-x-y=-6 .(2)

2x-3y=-3

- 2x - 2y = - 12

2x - 3y = - 3 (+)

-----------------------

- 5y = - 15 (-1)

5y = 15

y = 15/5

y = 3

- x - y = - 6 (-1)

x + y = 6

x + 3 = 6

x = 6 - 3

x = 3