1. what is the solution of the system
3x - y = 142
4x + y = 21
a (-5,3)
b (4, -2)
c (5, 1)
contained dimocanda

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + 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?

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!