How do you solve (x-3)^2 = 5(x3)2=5?

2 Answers
Jun 27, 2018

See a solution process below:

Explanation:

First, put the equation in standard quadratic form:

(x - 3)^2 = 5(x3)2=5

(x - 3)(x - 3) = 5(x3)(x3)=5

x^2 - 3x - 3x + 9 = 5x23x3x+9=5

x^2 - 6x + 9 = 5x26x+9=5

x^2 - 6x + 9 - color(red)(5) = 5 - color(red)(5)x26x+95=55

x^2 - 6x + 4 = 0x26x+4=0

We can now use the quadratic equation to solve this problem:

The quadratic formula states:

For color(red)(a)x^2 + color(blue)(b)x + color(green)(c) = 0ax2+bx+c=0, the values of xx which are the solutions to the equation are given by:

x = (-color(blue)(b) +- sqrt(color(blue)(b)^2 - (4color(red)(a)color(green)(c))))/(2 * color(red)(a))x=b±b2(4ac)2a

Substituting:

color(red)(1)1 for color(red)(a)a

color(blue)(-6)6 for color(blue)(b)b

color(green)(4)4 for color(green)(c)c gives:

x = (-color(blue)(-6) +- sqrt(color(blue)(-6)^2 - (4 * color(red)(1) * color(green)(4))))/(2 * color(red)(1))x=6±62(414)21

x = (6 +- sqrt(36 - 16))/2x=6±36162

x = (6 +- sqrt(20))/2x=6±202

x = (6 - sqrt(4 * 5))/2x=6452; x = (6 + sqrt(4 * 5))/2x=6+452

x = (6 - sqrt(4)sqrt(5))/2x=6452; x = (6 + sqrt(4)sqrt(5))/2x=6+452

x = (6 - 2sqrt(5))/2x=6252; x = (6 + 2sqrt(5))/2x=6+252

x = 6/2 - (2sqrt(5))/2x=62252; x = 6/2 + (2sqrt(5))/2x=62+252

x = 3 - sqrt(5)x=35; x = 3 + sqrt(5)x=3+5

Jun 27, 2018

x=3+sqrt5x=3+5 and x=3-sqrt5x=35

Explanation:

Let's take the square root of both sides. This gives us

x-3=+-sqrt5x3=±5

We can add 33 to both sides to get

x=3+sqrt5x=3+5 and x=3-sqrt5x=35

Hope this helps!