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Solve quadratics by taking swuare roots

Solve quadratics by taking swuare roots-example-1

1 Answer

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Answer:

x = 4 or x = -6

Explanation:

Recall that to solve a quadratic equation by taking the square root of each side, you must follow this pattern:

The solutions of the quadratic equation

X² = k

are

X = ±√k

where X is an expression containing a variable, and k is a number.

Let's look at the problem in this post and put in the form above.

2(x + 1)² + 5 = 55

We need the square of an expression equaling a number, so we solve for (x + 1)².

2(x + 1)² + 5 = 55

Subtract 5 from both sides.

2(x + 1)² = 50

Divide both sides by 2.

(x + 1)² = 25

Now we have the square of an expression on the left side and a number on the right side.

We take the square root of both sides and apply the ± sign to the right side.

x + 1 = ±√25

x + 1 = ±5

x + 1 = 5 or x + 1 = -5

x = 4 or x = -6

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