I am attaching a picture of the question as you can see the answer has already been picked well my teacher wants me to show how she got that answer.

From the properties of the circle we know that:
[tex]\begin{gathered} 6(2x-2+6)=5(31+5) \\ 6(2x+4)=5(36) \\ 12x+24=180 \\ 12x=180-24 \\ 12x=156 \\ x=\frac{156}{12} \\ x=13 \end{gathered}[/tex]This comes from the fact that If two secants are drawn to a circle from one exterior point, then the product of the external segment and the total length of each secant are equal. In this case this means that:
[tex]DE\cdot DF=DC\cdot DB[/tex]Now that we know the value of x we plug it in the expression for EF:
[tex]2(13)-2=26-2=24[/tex]Therefore segment EF is equal to 24.