Which property is illustrated by this problem 14+18 = 18 + 14 additive identity additive property of addition commutative property of addition

The figure above shows the lengths of thesides of a rectangle in cm. find the valuesof x and y and then the area of the rectangle. sides: top= 3x - yleft= 3y + 4bottom= 2x + yright= 2x - 3 use both methods, elimination and substitution, if possible.

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?

Ineed i been stuck on this question since yesterday