First, we have that the equation to calculate the reflection over the x-axis is:
![r_x(x,y)=(x,-y)](https://img.qammunity.org/2023/formulas/mathematics/high-school/t3cmxlsjbyfxbvv8dz83iouf2undeynt4t.png)
And the forumal for the reflection of point 'a' across the point 'p' is:
![T_p(a)=(2p_1-a_1,2p_2-a_2)](https://img.qammunity.org/2023/formulas/mathematics/college/22sh942urf85z9lnndgugpccux8kzpqdhj.png)
then, for the point C(-1,3), we have the following:
![\begin{gathered} (T_((-2,3))\circ r_x)(C)=(T_((-2,3))\circ r_x)(-1,3)_{}_{} \\ =T_((-2,3))(r_x(-1,3))=T_((-2,3))(-1,-3)=(2(-2)-(-1),2(3)-(-3)) \\ =(-4+1,6+3)=(-3,9) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2moaog8s41revl9zmoxefb7eueyp7f4jqn.png)
therefore, the image of C(-1,3) under the transformations is (-3,9)