How do you use completing the square method to solve $4x^2+5x=-1$ ?

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Answer 1 · 2018-03-24T06:05:02

$x =-1/4$
$x=-1$

$4x^2+5x=-1$

$4x^2+5x+1=0$

$(2x)^2+5x+1=0$

$(2x)^2+2×(2x)×(5/4)+(5/4)^2-(5/4)^2+1=0$

$(2x+5/4)^2 -(5/4)^2+1=0$

$(2x+5/4)^2 =25/16-1$

$(2x+5/4)^2 =9/16$

$2x+5/4=+-sqrt(9/16)$

$2x+5/4=3/4 or 2x+5/4=-3/4$

$2x=3/4-5/4 or 2x= -3/4-5/4$

$2x=-2/4 or 2x= -8/4$

$x=-1/4 or x=-1$

How do you use completing the square method to solve 4x^2+5x=-14x^2+5x=-1?