The roots of the quadratic equation are -3/2 and -1/2
This is an equation in which we use to solve or find the roots of a quadratic equation by simply substituting the variables.
To solve this problem, we have to use quadratic formula which is given as
[tex]x=\frac{-b +- \sqrt{b^2-4ac} }{2a}\\[/tex]
Let's rearrange this equation
[tex]4x^2+21=-20x\\4x^2+20x+21=0[/tex]
where
Substitute the values and solve
[tex]x=\frac{-b+- \sqrt{b^2-4ac} }{2a}\\x = \frac{-20+-\sqrt{20^2-(4*4*21)} }{2*4} \\x= \frac{-20+-(8)}{8}\\ x = \frac{-3}{2} \\or\\x = -\frac{1}{2}[/tex]
From the calculation above, the roots of the equation are
Learn more on quadratic formula here
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