What is the solution to the equation 3c

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

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 statement is true? 2x^2-9x+2=-1