If |x^2 − 42| = x, which of the following could be the value of x?  Choose the correct choice from the following answers:
A) –7 B) –6 C) 2 D) 6 E) 14
The LHS is not negative, so the RHS is also not negative. Thus x &gt;= 0.   First, let's assume that x^2-42 is negative.   -(x^2 - 42) = x   x^2 + x - 42 = 0   (x+7)(x-6) = 0   x = 6 or x = -7 (However, x can not be negative.)   Then x = 6 is a possible value for x.   The answer is 6.
<result>D</result>
If |x^2 − 42| = x, which of the following could be the value of x?