Question

Solve x2 - 4x = 12 by completing the square, show work please!!

Answer 1

b is -4

half of b is -2


this answer, -2 times itself equals 4 and now we add 4 to both sides

x^2 - 4x + 4 = 12 +4

Do you know the next step?

Answer 2

meverett, I understand what you're trying to do here, but your approach is useless without first explaining the general method of approach for completing the square.

Answer 3

You should either provide the complete solution, or if you're going to do it your way, provide the general method of approach

Answer 4

I motivate not hate ...

Answer 5

You assume something is "hate" ing on you.

Answer 6

Just transfer the 12 to the left and you can "break" it into (x+2)(x-6)=0 From that it follows, x=-2 and x=6

Answer 7

So in general, when solving quadratic equations using the complete the square method, you begin with a general form ax^2 + bx = c.

Then you add (b/2)^2 to both sides, creating a perfect square on the left side.

Once we have a perfect square on the left side, we put it in the form (x-b)^2 then solve for x algebraically.

In this particular case, we have x^2 -4x = 12. So a = 1, b = -4 and c = 12
Since b = -4, (b/2)^2 = =(-4/2)^2 = (-2)^2 = 4

so b/2 = 4

Now we add 4 to both sides:

x^2-4x +4 = 12 +4

Then put the left side in the completed square form:

(x-2)^2 = 16

Now we can solve for x algebraically:

x - 2 = +-sqrt{16}

x = +4 + 2
x = -4 + 2

x = 6
x = -2

Answer 8

Thank you for the detailed explanation!!!

Answer 9

yw