Question
Can 2x^2+5x+10=0, be factored? If not, how do use, completing the square method for this equation? Thanks!
Answers
Reiny
2*10 = 20
are there two factors of 20 which add up to 5?
no, so it does not factor.
divide each term by 2
x^2+(5/2)x+5=0
x^2+(5/2)x + ? = -5 + ?
x^2+(5/2)x + 25/16 = -5 + 25/16
(x+5/4)^2 = -55/16
x+5/4 = ± √-55/4
x = (-5 ± i√55)/4
are there two factors of 20 which add up to 5?
no, so it does not factor.
divide each term by 2
x^2+(5/2)x+5=0
x^2+(5/2)x + ? = -5 + ?
x^2+(5/2)x + 25/16 = -5 + 25/16
(x+5/4)^2 = -55/16
x+5/4 = ± √-55/4
x = (-5 ± i√55)/4