Respuesta :

Answer:

Given  

x 2 − 2 x = 15

add 1 to both sides to get:

6 = x 2 −

2 x + 1 = ( x − 1 ) 2

So  x − 1 = ± √ 16 = ± 4

Add  1  to both sides to get:

x = 1 ± 4

That is:  x = − 3

or

x = 5