If |x^2 − 30| = x, which of the following could be the value of x?
Options:
A) -6
B) -5
C) 1
D) 5
E) 15
The LHS is not negative, so the RHS is also not negative. Thus x &gt;= 0.   First, let's assume that x^2-30 is negative.   -(x^2 -30) = x   x^2 + x - 30 = 0   (x+6)(x-5) = 0   x = 5 or x = -6 (However, x can not be negative.)   Then x = 5 is a possible value for x.   The answer is 5.
<result>D</result>
If |x^2 − 30| = x, which of the following could be the value of x?