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"#