Answer: B) 6
Step-by-step explanation:
"The Corresponding Angles Theorem states: If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent"
So, in this case both expressions are equal (have the same angle measurement) so we can solve for x
(12x+3)=(11x+9)
=12x-11x=9-3
x=9-3
x=6
