Question

Como resolver esses sistemas:
1){2x+y=1
x-2y=-7
2){2x+y=5
x-2y=0
3){x+y=5
x/3+y/2=2

Answer 1

Ola Fernanda

1)

2x + y = 1
x - 2y = -7
4x + 2y = 2

5x = -5
x = -1

-2 + y = 1
y = 3

2)

2x + y = 5
x -2y = 0
4x + 2y = 10

5x = 10
x = 2

4 + y = 5
y = 1

3)

x + y = 5
x/3 + y/2 = 2

2x + 3y = 12
3x + 3y = 15

x = 3

3 + y = 5
y = 2

.

Answer 2

fica assim:
1)2x + y = 1
x - 2y = -7
4x + 2y = 2
5x = -5
x=-5/5
x = -1
-2 + y = 1
y=1+2
y = 3

2)2x + y = 5
x -2y = 0
4x + 2y = 10

5x = 10
x=10/5
x = 2

4 + y = 5
y=5-4
y = 1

3)x + y = 5
x/3 + y/2 = 2

2x + 3y = 12
3x + 3y = 15
x = 3
3 + y = 5
y=5-3
y = 2