This inequality can be turned into a quadratic inequality.
Before that, there's a tricky bit to these type of questions. The denominator.
\(\frac{x-7}{x+12} ≥ 0\)
Test takers could potentially make mistakes because it is so easy to go wrong when you're in a rush. But this can be overcome with a little bit of observation.
The RHS is \(0\).
So we ought to understand that the RHS should comply with this information. If the denominator of \(\frac{x-7}{x+12}\) were to be zero, the LHS would be undefined. Thus, an important inference - \(x\)can never be equal to \(-12\)
keeping this information in mind, one can proceed to simplify this expression.
multiply both sides of the inequality with \((x+12)^2\).
\(=> (x-7)(x+12) ≥ 0\)
You'll arrive at the roots 7 and -12. Look at the inequality again and determine the sign. The ranges for x will be of the form \(x ≥ 7\) and \(x < -12\).
In terms of the format that the answer choices take
\(x ∈ (-∞, -12)\) and \([7, ∞)\)
Notice the circular bracket in\(x ∈ (-∞, -12)\) indicating that x is not equal to 12.
The answer is C.