Respuesta :

wegnerkolmp2741o

Answer:

add 4

Step-by-step explanation:

x^2-4x

Take the coefficient of the x term

-4

Divide it by 2

-4/2 =-2

Square it

(-2)^2 = 4

This is what we add to each side

x^2-4x +4 = 4

Answer:

4

Step-by-step explanation: