# How do you solve #x^2+8x-2=0# using completing the square?

##### 3 Answers

**Solution:**

#### Explanation:

Solution:

Take the second coefficient, divide it by 2, and square it, to complete the square, and obtain the solutions:

#### Explanation:

To complete the square, take the second coefficient (the one next to the

In this case, that would be

Add this number to both sides of the original equation:

This gives us 2 possible solutions:

#### Explanation:

#"add 2 to both sides"#

#x^2+8x=2#

#"add "(1/2"coefficient of the x-term")^2" to both sides"#

#x^2+2(4)x color(red)(+16)=2color(red)(+16)#

#(x+4)^2=18#

#color(blue)"take the square root of both sides"#

#sqrt((x+4)^2)=+-sqrt18larrcolor(blue)"note plus or minus"#

#x+4=+-sqrt18=+-sqrt(9xx2)=+-3sqrt2#

#"subtract 4 from both sides"#

#x=-4+-3sqrt2larrcolor(red)"exact values"#

#x~~-8.24" or "x~~0.24" to 2 dec. places"#