Can someone help me?

What is the reflection image of (5,-3) across the line y = -x?

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

What are the coordinates of the point that is 1/3 of the way from a to b? a (2,-3) b (2,6)