Answer
180$^{\circ}$ - x$^{\circ}$
Work Step by Step
the sum of two angles a$^{\circ}$ and b$^{\circ}$, is a$^{\circ}$ + b$^{\circ}$ = 180$^{\circ}$
Therefore the angles a$^{\circ}$ and b$^{\circ}$are called supplementary angles.
The supplement of angle a$^{\circ}$ is b$^{\circ}$which can be written as b$^{\circ}$ = 180$^{\circ}$ - a$^{\circ}$
Hence supplement of x$^{\circ}$ = 180$^{\circ}$ - x$^{\circ}$
