Write the Algebraic Expression Described $180 ^ { \circ }$ If One Angle of a Triangle Measures

Multiple Choice

Write the algebraic expression described. Simplify if possible.
-The sum of the angles of a triangle is $180 ^ { \circ }$ . If one angle of a triangle measures $x ^ { \circ }$ and a second angle measures $( 9 x + 18 ) ^ { \circ }$ , express the measure of the third angle in terms of $x$ .

A) $( 198 - 10 x ) ^ { \circ }$
B) $( 162 - 9 x ) ^ { \circ }$
C) $( 162 - 10 x ) ^ { \circ }$
D) $( 162 + 10 x ) ^ { \circ }$