Given the information in the picture, we have that the angle 135° is corresponding angle with the supplement of angle 1. This is:
Then, since the angle that measures 135° and angle 1 are supplemetary, we have the following:
[tex]\begin{gathered} \measuredangle1=4x-3 \\ \measuredangle1+135=180 \\ \Rightarrow4x-3+135=180 \\ \Rightarrow4x=180+3-135=48 \\ \Rightarrow x=\frac{48}{4}=12 \\ x=12 \end{gathered}[/tex]
therefore, x=12
