Question

Resolva os sistemas abaixo.
A) {2x-2y=12
{X+2y= 11


B) {-3x-2y=8
{ X-5y=3

C) {3x-2y= -1
{2x+5y=12

Answer 1

Oi Vitoria

a)

x - y = 6
x + 2y = 11

2y + y = 11 - 6 = 5
3y = 5
y = 5/3

x = y + 6 = 5/3 + 18/3 = 23/3 

S = (23/3, 5/3) 

b)

3x + 2y = -8
x - 5y = 3
-3x + 15y = -9

17y = -17
y = -1

3x - 2 = -8
3x = -6
x = -2 

S = (-2,-1)

c)

3x - 2y = -1
2x + 5y = 12

15x - 10y = -5
4x + 10y = 24

19x = 19
x = 1

2 + 5y = 12
5y = 10
y = 2

S = (1,2)