Question

Solve x2 - 8x + 3 = 0 by completing the square.

Which equation is used in the process?


(x - 4)2 = 0

(x - 4)2 = 13

(x - 4)2 = 19

Answer 1

@d3Xter

Answer 2

Here's a page that will explain completing the square:
http://1728.org/quadr2.htm
(The second half of the page explains about deriving the quadratic formula so just ignore that).
Completing the square:

x2 - 8x + 3 = 0

Move the "non X" term to the right
x² -8x = -3

Divide the equation by the coefficient of X²
That doesn't have to be done because there is no coefficient.

get the coefficient of x
divide by 2
square it
add it to both sides of the equation
-8/2 = -4
-4² = 16

x² -8x + 16 = -3 +16

Take the square root of both sides:
(x-4) = sqrt(13)
x = sqrt (13) + 4

x1 = 3.6055512755 + 4
x1 = 7.6055512755

x2 = -sqrt(13) + 4
x2 = -3.6055512755 + 4
x2 = 0.3944487245

Answer 3

thank you !!

Answer 4

u r welcome
glad to help.