Alvin is 13 years older than Elga. The sum of their ages is 87 . What is Elga's age?

Solve |2x - 5| = 4 if anyone could , that would be great

1. what is the measure of ∠abc? what is the measure of ∠abd?

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?