Question

Is my answer correct? ;)

What value is added to both sides of the equation x2 - 8x = -10 in order to solve by completing the square?

Answer: I know it would be 16 if the answer to the problem was -11, but in this case, the answer I got was "-8"

Answer 1

what do you mean by "I know it would be 16 if the answer to the problem was -11"

Answer 2

I applied a certain step, and I figured I'd do the opposite for this problem....

Answer 3

and what step was that

Answer 4

a^2-2ab+b^2 = (a-b)^2
a = x
=> 2ab = 8x
=> b = 8x/2x
=> b = 4
=> b^2 = 16
16 is to be added to both sides of the equation.

Answer 5

good, you can also use this shortcut

x coefficient: -8

cut the x coefficient in half: -8/2 = 4

square that last result: 4^2 = 16

Answer 6

thank you

Answer 7

yw

Answer 8

that makes it easier, thanks :)