Q. Rewrite the equation by completing the square.x2+4x−21=0(x+□)2=□
Rewrite equation: Rewrite the equation in the form of x2+bx=c.We start with the equation x2+4x−21=0 and add 21 to both sides to isolate the x2 and x terms on one side.x2+4x−21+21=0+21x2+4x=21
Isolate x2 and x terms: Find the number to complete the square.To complete the square, we need to add (b/2)2 to both sides of the equation, where b is the coefficient of x. In this case, b=4.(4/2)2=(2)2=4We add 4 to both sides of the equation.x2+4x+4=21+4x2+4x+4=25
Find completing the square number: Factor the left side of the equation.The left side of the equation is now a perfect square trinomial, which can be factored into (x+2)2.(x+2)2=25
Factor left side of equation: Write the completed square form of the equation.The completed square form of the equation is (x+2)2=25.
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