Question

x^2-4x=1 what number must you add to complete this square?

Answer 1

Please help it would be appreciated:)

Answer 2

Remember,Half and square

Answer 3

4

\[x^2-4x+4=(x-2)^2\]

Answer 4

think "half of -4 is..."
i get -2
then think "(-2) squared is..." 4. so you need to add 4

Answer 5

Thank you and yes i remember imranmeah91.. but does that apply to all equations?

Answer 6

\[x^2-4x+(\frac{-4}{2})^2=1+(\frac{-4}{2})^2\]
\[x^2-4x+4=1+4\]
\[(x-2)^2=5\]
\[x-2=\pm \sqrt{5}\]
now just add 2 to both sides

Answer 7

\[x=2 \pm \sqrt{5}\]

Answer 8

Yes, all, as long as there is 1 next to x^2 terms

Answer 9

for example
x^2 + 8x= -3?
run me through that one please.. im sorry

Answer 10

half of 8 is 4
square of 4 is 16

So 16

Answer 11

okay thank you:) im a new fan

Answer 12

x^2-4x = 1 x^2 - 4x -1 = 0 you want to have: (x-2)^2 = (2-x)^2 = x^2 + 4 - 4x so you must add 5 to -1 X^2 -4= 1+5