How do you solve the quadratic equation by completing the square: #x^2 + 4x = 21#?
To obtain, add this term to each side of the equation.
Currently, the equation's left side can be expressed as
This implies that you currently possess
Take each side's square root.
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To solve the quadratic equation by completing the square (x^2 + 4x = 21), follow these steps:

Move the constant term to the other side of the equation: (x^2 + 4x  21 = 0)

Add and subtract the square of half the coefficient of the (x) term: (x^2 + 4x + 4  4  21 = 0)

Rewrite the expression as a perfect square trinomial: ((x + 2)^2  25 = 0)

Move the constant term to the other side of the equation: ((x + 2)^2 = 25)

Take the square root of both sides (remembering to consider both positive and negative roots): (x + 2 = ±\sqrt{25})

Solve for (x): (x + 2 = ±5)

Subtract 2 from both sides: (x = 2 ± 5)

The solutions are: (x = 2 + 5) and (x = 2  5)
Which simplifies to: (x = 3) and (x = 7)
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When evaluating a onesided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a onesided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a onesided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a onesided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
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