# What is the range of f(x) = abs(-2x-1)?

$- 2 x - 1$ can be used to generate any Real number with an appropriate value selection for $x$
$\left\mid - 2 x - 1 \right\mid$ restricts the generated values to those greater than or equal to zero (by definition of absolute value).
Range of $f \left(x\right) = \left\mid - 2 x - 1 \right\mid$
is $\left[0 , + \infty\right)$