Answer
$h(x)$ is not one-to-one.
Work Step by Step
The function $h(x)=x^2-2x$ is not one-to-one because it fails the horizontal line test (the graph is a shifted parabola). We can show that it has the same $y$ value for two different $x$ values:
$h(0)=0^2-2*0=0$
$h(2)=2^2-2*2=4-4=0$
Thus the function is not one-to-one.
