To find the equation for the supplementary angles, we need to recall the definition of supplementary angles: two angles are supplementary if the sum of their measures is 180 degrees.
Given:
- m<ABC = 135 degrees
- m<CBD = 9x degrees
Since these two angles are supplementary, we can set up the equation as follows:
\[ m<ABC + m<CBD = 180 \]
Substituting the given measures into the equation:
\[ 135 + 9x = 180 \]
So, the correct equation to solve for \( x \) is:
\[ 9x + 135 = 180 \]
Therefore, the answer is:
9x + 135 = 180