Which number line represents the solutions to $-2|x|=-6$ ?
The objective is to identify the solutions to the absolute value equation \(-2|x| = -6\) and understand how these solutions are represented on a number line. An absolute value expression, denoted by \(|x|\), represents the non-negative distance of a number \(x\) from zero on the number line. Our strategy will be to isolate the absolute value term and then solve for \(x\).
To solve the equation \(-2|x| = -6\), we first isolate the term \(|x|\). We do this by dividing both sides of the equation by \(-2\):
\[\frac{-2|x|}{-2} = \frac{-6}{-2}\]
Simplifying this, we get:
\[|x| = 3\]
This equation tells us that the distance of \(x\) from zero is exactly \(3\). On a number line, there are two points that are exactly \(3\) units away from zero: \(3\) and \(-3\). Thus, the solutions to the equation are \(x = 3\) and \(x = -3\).
The solutions \(x = 3\) and \(x = -3\) correspond to specific locations on a number line. To represent these solutions, we draw a number line and mark points at \(-3\) and \(3\). These two distinct points indicate the values of \(x\) that satisfy the original equation \(-2|x| = -6\). Hence, the correct representation is a number line with points at \(-3\) and \(3\). Therefore, the solutions to the equation are \(\boxed{-3, 3}\).
Absolute value equations are essential in many real-world scenarios, such as measuring tolerances in manufacturing. For example, if a machine part is designed to be 10 cm long with a tolerance of 0.1 cm, the actual length \(L\) must satisfy \(|L - 10| \leq 0.1\). This inequality ensures that the deviation from the target length is within acceptable limits, demonstrating how absolute values help define safe operating ranges and maintain precision in engineering and design.