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Rewrite the equation by completing the square - 4x^2 +20x +25 =0

User Mshaps
by
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1 Answer

4 votes

Answer:


\left(x-(5)/(2)\right)^2=(25)/(2)

Explanation:

I am not completely sure if you just wanted me to write it in square form, so I will show the process of writing it in square form and how to find the solution.


-4x^2+20x=-25 start by moving 25 to the right side


(-4x^2+20x)/(-4)=(-25)/(-4) divide both sides by -4

=
x^2-5x=(25)/(4)

Now we rewrite the equation in the form
\:x^2+2ax+a^2

=
x^2-5x+\left(-(5)/(2)\right)^2=(25)/(2) apply perfect square formula:
\left(a-b\right)^2=a^2-2ab+b^2

=
\left(x-(5)/(2)\right)^2=(25)/(2) -- square form

Solutions to the quadratic equation:

Possible solutions:
x=(5)/(√(2))+(5)/(2) and
\:x=-(5)/(√(2))+(5)/(2)

User Lachlan Young
by
9.2k points