How do you solve using the completing the square method #x^2 +5x +4=0#?

1 Answer
May 3, 2017

Answer:

#x=-4" or "x=-1#

Explanation:

#"To solve by "color(blue)"completing the square"#

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

#"that is " (5/2)^2=25/4#

#rArr(x^2+5xcolor(red)(+25/4))+4=0color(red)(+25/4)#

#rArr(x+5/2)^2+4=25/4#

#rArr(x+5/2)^2=25/4-4=9/4#

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

#sqrt((x+5/2)^2)=+-sqrt(9/4)#

#rArrx+5/2=+-3/2#

#rArrx=-5/2+-3/2#

#rArrx_1=-5/2-3/2=-4" and " x_2=-5/2+3/2=-1#