For this case we have the following system of equations:
[tex]3x + 7y = 31\\-3x-2y = -1[/tex]
We multiply the first equation by 2:
[tex]6x + 14y = 62[/tex]
We multiply the second equation by 7:
[tex]-21x-14y = -7[/tex]
We add the equations:
[tex]6x-21x + 14y-14y = 62-7\\-15x = 55\\x = \frac {55} {- 15}\\x = -3.67[/tex]
We convert to a mixed number:
[tex]x = - 3 \frac {2} {3}[/tex]
Answer:
The value of x is [tex]- 3 \frac {2} {3}[/tex]
Option B
