Given:
The system of equations is:
Line A: [tex]y=x-4[/tex]
Line B: [tex]y=3x+4[/tex]
To find:
The solution of given system of equations.
Solution:
We have,
[tex]y=x-4[/tex] ...(i)
[tex]y=3x+4[/tex] ...(ii)
Equating (i) and (ii), we get
[tex]x-4=3x+4[/tex]
[tex]-4-4=3x-x[/tex]
[tex]-8=2x[/tex]
Divide both sides by 2.
[tex]-4=x[/tex]
Substituting [tex]x=-4[/tex] in (i), we get
[tex]y=-4-4[/tex]
[tex]y=-8[/tex]
The solution of system of equations is (-4,-8).
Now verify the solution by substituting [tex]x=-4, y=-8[/tex] in the given equations.
[tex]-8=-4-4[/tex]
[tex]-8=-8[/tex]
This statement is true.
Similarly,
[tex]-8=3(-4)+4[/tex]
[tex]-8=-12+4[/tex]
[tex]-8=-8[/tex]
This statement is also true.
Therefore, (-4,-8) is a solution of the given system of equations, because the point satisfies both equations. Hence, the correct option is C.