To find the equation for the two adjacent angles, we start with the measures given:
- One angle is \( x + 18 \) degrees.
- The other angle is \( x \) degrees.
Since these two angles are adjacent (next to each other) and are inside a 90° angle, their sum should equal 90 degrees. Therefore, we can set up the equation as follows:
\[ (x + 18) + x = 90 \]
This equation represents the sum of the two angles being equal to 90°.
Now you have the equation:
\[ (x + 18) + x = 90 \]
You can solve this equation to find the value of \( x \).