[tex]\textsf{Find the supplement of } 75^{\circ}[/tex]
[tex]\textsf{SOLUTION:}[/tex]
[tex]\textsf{Let the supplement of } 75^{\circ} \: \textsf{be x.}[/tex]
[tex]75^{\circ} + \text{x} = 180^{\circ}[/tex]
[tex]75^{\circ} + \text{x} - 75^{\circ} = 180^{\circ}- 75^{\circ}[/tex]
[tex]\text{x} = \boxed{105^{\circ}}[/tex]
[tex]\textsf{ANSWER:}[/tex]
[tex]\textsf{C. }105^{\circ}[/tex]
