Since lines m and n are parallel this means that the angles 1 and 2 are congruent, this comes from the fact that alternate interior angles between two parallel lines are equal. Then:
[tex]\begin{gathered} 7x=5x+30 \\ 7x-5x=30 \\ 2x=30 \\ x=\frac{30}{2} \\ x=5 \end{gathered}[/tex]Therefore x=15° and the answer is option 2
