How do you solve x^2 - 6x =13 by completing the square?

2 Answers
Mar 24, 2018

x=3+sqrt22
x=3-sqrt22

Explanation:

Given -

x^2-6x=13

x^2-6x+9=13+9

(x-3)^2=22

x-3=+-sqrt22

x=+-sqrt22 +3

x=3+sqrt22
x=3-sqrt22

Mar 24, 2018

x= sqrt22+3 or -sqrt22+3

Explanation:

x^2 -6x =13

x^2 -6x -13=0

Multiply the equation by 4

4(x^2 -6x -13=0)

4x^2 -24x-52=0

(2x)^2 -24x-52=0

(2x)^2-2×(2x)×(6)+6^2-6^2-52=0

(2x-6)^2 -36-52 =0

(2x-6)^2 -88=0

(2x-6)^2=88

2x-6= +-sqrt 88

2x-6=sqrt 88 or 2x-6=-sqrt88

2x-6=2sqrt22 or 2x-6=-2sqrt22

x= sqrt22+3 or x= -sqrt22+3