I don't understand quite how to do this one I don't know what angle I have to simplify I did it all together still I don't get it. If you answer this please show the step so I can better understand.

Answer:
x=18
Step-by-step explanation:
This two angles are complementary, which means that they both add up to 90. So we could set up the equation:
(4x+1)+(x-1)=90
5x=90
x=[tex]\frac{90}{5}[/tex]
x=18
Have a nice day! :)