Answer: C
Step-by-step explanation:
To solve for 12, we can use eliminate or substituion to solve our system of equations. Let's use elimination method.
[tex]\left \{ {{3f-2k=10} \atop {-3f-2k=14}} \right.[/tex]
Let's add the equations together. This way, 3f+(-3f)=0
[tex]-4k=24[/tex] [divide both sides by -4]
[tex]k=-6[/tex]
Now that we know k, we can plug it into either equation to find f.
[tex]3f-2(-6)=10[/tex] [multiply]
[tex]3f+12=10[/tex] [subtract both sides by 12]
[tex]3f=-2[/tex] [divide both sides by 3]
[tex]f=-\frac{2}{3}[/tex]
Now that we have f and k, we know that C is the correct answer.
