Step-by-step explanation:
We are given the following coordinates for a figure on the coordinate plane;
![\begin{gathered} P(2,-12) \\ Q(-3,13) \\ R(-5,-15) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/x6rd8m0uiqqsnsanqckj4f6vc5nwk9uap1.png)
To reflect any figure or any set of coordinates across the x-axis, we shall apply the rule;
![(x,y)\rightarrow(x,-y)](https://img.qammunity.org/2023/formulas/mathematics/college/d7a29ae1nc5itoub5zbvfqbwxpczq9rzr6.png)
Note that the x-coordinate remains the same whereas, the y-coordinate changes its sign.
Imagine folding a graph page in two equal halves along the horizontal axis. You'll observe the y-coordinates will switch sides from top to bottom (positive to negative) or bottom to top (negative to positive). The x-coordinate remains the same since moving the folded page does not affect values along the horizontal line.
Therefore, for the vertices given, the reflection across the x-axis would be;
![P(2,-12)\rightarrow P^(\prime)(2,12)](https://img.qammunity.org/2023/formulas/mathematics/college/e7emxq102a0ginowv4x97d1xtrjvhk4bw4.png)
![Q(-3,13)\rightarrow Q^(\prime)(-3,-13)](https://img.qammunity.org/2023/formulas/mathematics/college/ige4c55y99iz7oh85fal1g2sfyc0a2t8jv.png)
![R(-5,-15)\rightarrow R^(\prime)(-5,15)](https://img.qammunity.org/2023/formulas/mathematics/college/t1lr9btqxxoy5c1h8fsg3e9odbuhp2iwqo.png)
ANSWER:
The coordinates of the reflection across the x-axis therefore will be;
![\begin{gathered} P^(\prime)(2,12) \\ Q^(\prime)(-3,-13) \\ R^(\prime)(-5,15) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/um0fyjye6htjbysx102yauxb3wmobysjwf.png)