-7-4x=18

What does x stand for?

PLEASE!!

First option.

Step-by-step explanation:

 You need to remember that:

1. Complementary angles are defined as those angles whose sum is 90 degrees.

2. Adjacent angles are those angles that have a common side and a common vertex.

3. Vertical angles are defined as those angles that are opposite to each other and share the same vertex.

4. Supplementary angles are defined as those angles whose sum is 180 degrees.

In this case you can notice that the angle formed  by the intersection of of the vertical line and the horizontal line measure 90 degrees. Therefore, if you add the angle 1 and the angle 2, you will get 90 degrees.

Based on the above you can conclue that the angles 1 and 2 are Complementary angles.