what are the coordinates of D’

Answer:
(-2,-1)
Step-by-step explanation:
Reflection across the x-axis is: [tex](x,y)\rightarrow(x,-y)[/tex]
We need to multiply the y-value of the pre-image by negative one to get reflected across the x-axis.
1 * -1 = -1
So:
[tex](-2,1)\rightarrow(-2,-1)[/tex]
D' should be (-2,-1).