Select the correct answer.

Which equation is equivalent to the given equation?

[tex]\[ x^2 + 16x = 22 \][/tex]

A. \((x+8)^2 = 86\)

B. \((x+16)^2 = 278\)

C. \((x+8)^2 = 38\)

D. [tex]\((x+4)^2 = 22\)[/tex]



Answer :

To solve the given equation \( x^2 + 16x = 22 \) and find an equivalent one, we will complete the square. Here is a step-by-step solution:

1. Start with the given equation:
[tex]\[ x^2 + 16x = 22 \][/tex]

2. Complete the square on the left-hand side:

- Take the coefficient of \( x \), which is 16.
- Divide it by 2:
[tex]\[ \frac{16}{2} = 8 \][/tex]
- Square the result:
[tex]\[ 8^2 = 64 \][/tex]

3. Add and subtract 64 to the equation to maintain equality:
[tex]\[ x^2 + 16x + 64 - 64 = 22 \][/tex]

4. Rewrite the left side as a perfect square:
[tex]\[ (x + 8)^2 - 64 = 22 \][/tex]

5. Move the constant term (-64) to the right-hand side of the equation:
[tex]\[ (x + 8)^2 = 22 + 64 \][/tex]

6. Combine the terms on the right-hand side:
[tex]\[ (x + 8)^2 = 86 \][/tex]

Therefore, the equation that is equivalent to the given equation \( x^2 + 16x = 22 \) is:

A. \((x + 8)^2 = 86\)

So, the correct answer is:
[tex]\[ \boxed{(x+8)^2=86} \][/tex]

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