How do you solve (x-3)^2 = 5 using the quadratic formula?

1 Answer
May 9, 2018

(x-3)^2=5

x_1=3+\sqrt(5)
x_2=3 -\sqrt(5)

Explanation:

(x-3)^2=5
x^2-6*x+9=5
x^2-6*x+9-5=0
x^2-6*x+4=0

a*x^2+b*x+c=0

x_(1,2)=(-b +- \sqrt(b^2-4*a*c))/(2*a)

a=1
b=6
c=4

x_(1,2)=(-(-6) +- \sqrt(6^2-4*1*4))/(2*1)=
=(6 +- \sqrt(36-16))/(2*1)=
=(6 +- \sqrt(20))/(2)=
=(6 +- \sqrt(4*5))/(2)=
=(6 +- 2*\sqrt(5))/(2)=
=3 +-\sqrt(5)

x_1=3+\sqrt(5)
x_2=3 -\sqrt(5)