How do you solve #x^2 - 6x = 16# by completing the square?
1 Answer
Sep 3, 2017
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#
