Positive linear association !
Carla = 5 years old
Jim = 2 years old
Peter = 15 years old
(Peter was 14 years old one year ago)
5+2=7
7x2=14 (14 is the age from one year ago meaning 15 is the current age)
15-2=13
2x^2 + 16x - 10 = 0
2(x^2 + 8x) - 10 = 0
2 [(x + 4)^2 - 16 ]- 10 = 0
[(x + 4)^2 - 16 - 5 = 0
(x + 4)^2 - 21 = 0
(x + 4)^2 = 21