Question

Resolva os sistemas

a) $\left \{ {{x+y=-3} \atop {3x+y=1}} \right.$
b)$\left \{ {{x+2y=12} \atop {3x-y=22} \right.$
c)$\left \{ {{-2x-6y=6} \atop {x+7y=-3} \right.$
d)$\left \{ {{5x-y=1} \atop {2x-3y=-10} \right.$
e)$\left \{ {{2x-y=6} \atop {-4x+2y=-12} \right.$
f)$\left \{ {{x-y=0} \atop {x+y=4} \right.$
g)$\left \{ {{x+3y=1} \atop {2x+6y=-2} \right.$

Answer 1

Oi Highmonster

a)

x + y = -3
3x + y = 1

3x - x = 1 + 3 = 4
2x = 4
x = 2

2 + y = -3
y = -3 - 2 = -5

b)

x + 2y = 12
3x - y = 22
6x - 2y = 44

7x = 56
x = 8

8 + 2y = 12
2y = 4
y = 2

c)

2x + 6y = -6
x + 7y = -3
2x + 14y = -6

14y - 6y = -6 + 6 = 0

y = 0
x = -3

d) 

5x - y = 1
2x - 3y = -10

15x - 3y = 3

15x - 2x = 13
13x = 13
x = 1

5 - y = 1
y = 4

e)

2x - y = 6
-4x+ 2y = -12
4x - 2y = 12
0 + 0 = 0
SPI

f)

x - y = 0
x + y = 4

2x = 4
x = 2
y = 2

g)

x + 3y = 1
2x + 6y = -2
2x + 6y = 2

SI