I have no idea how to solve this:
When solving x2 – 4x = –7 by completing the square what value is added to both sides of the equation?
A: 8

B: 4

C: 2

D: –2
Thank you so much! & Happy Holidays!

Question

I have no idea how to solve this: 
When solving x2 – 4x = –7 by completing the square what value is added to both sides of the equation?
A: 8

B: 4

C: 2

 D: –2
Thank you so much! & Happy Holidays!

ranga · Answer

When completing the square we divide the coefficient of x by 2 and add the square of that to both sides.

campbell_st · Answer

you need to add half the coefficient of the term in x squares to both sides

so the term is in is -4x  

the coefficient is -4 

halve it... -2 

now square it and add that value to both sides of the equation.

anonymous · Answer

Ohh, okay! Thanks guys, I'm pretty sure I have it now!

ranga · Answer

You are welcome.