Two angles are complementary if the sum of their measures is 90 degrees.
Given one angle is 46 degrees, we can find the measure of angle X (/_x) by using the following equation:
\[ 46 + X = 90 \]
To find X, subtract 46 from both sides:
\[ X = 90 - 46 \]
\[ X = 44 \]
So, the measure of angle X is 44 degrees.