Respuesta :

weirkai27

X = 1


Simple answer. Hope this helps.

ivana2103
(a+b)^2 = a^2 + 2ab + b^2
(a-b)^2 = a^2 - 2ab + b^2

(x+4)^2 - (x-5)^2 = 9
x^2 + 8x + 16 - (x^2 - 10x + 25) = 9
x^2 +8x + 16 - x^2 + 10x - 25 = 9
(the squared terms cancel out)

8x + 16 + 10x - 25 = 9
18x = 9 - 16 + 25
18x = 9 + 9
18x = 18
x = 1