Question

Resolva o sistema:
{2x + 4y = - 5
{3x - 7y = 0

Answer 1

{2x + 4y = - 5...(7)
{3x - 7y = 0...(4)

14x + 28y = - 35
12x - 28y = 0
_____________
26x............= - 35

x = - 35
.......____
.........26


2x + 4y = - 5

2(-35) + 4y = - 5
...___
...(26)

- 70 + 4y = - 5
..___
.. 26

4y = -5 + 70
................___
.................26

4y = - 130 + 26
.........________
.................26

4y = - 60
..........___
...........26

y = - 60
......____
........26
........__
.........4

y = - 60
.......____ x 4
.........26

y = - 240
.......____(÷2)
.........26

y = - 120
......_____
..........13