Please help Write the series using summation notation.

4. - 10 + 2 + 14 + 26 + 38 + 50 + 62 + 74

5. 6+13+32+69+

6. - 5/8 + 10/11 + 20/16 + 40/23

What number must you add to complete the square x^2+12x=16

What are the solution(s) to the quadratic equation x2 – 25 = 0? o x = 5 and x = -5ox=25 and x = -25o x = 125 and x = -125o no real solution

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?