|10 - x| = 4.
Which of the following options is the CORRECT solution set for the above equation?

A {6, 14}

explanation

The bars which surround the equation signify "absolute value". When you have an absolute value, it means that the expression is always positive or zero.
Thus, the equation |10 - x| = 4 has two solutions: x = 6, |10 - 6| = 4;
and x = 14, |10 - 14| =|- 4| =4.