How do you solve #x^2 - 6x = 16# by completing the square?

1 Answer
Sep 3, 2017

Answer:

#x=-2" or "x=8#

Explanation:

#"to complete the square"#

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

#"that is add "(-6/2)^2=9" to both sides"#

#rArrx^2+2(-3)xcolor(red)(+9)=16color(red)(+9)#

#rArr(x-3)^2=25#

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

#x-3=+-5larr" note plus or minus"#

#rArrx=3+-5#

#rArrx=3-5" or "x=3+5#

#rArrx=-2" or "x=8#