Q. What is the solution of the equation \(x^2 = 64\)?
Answer
Taking square roots: \(x=\pm\sqrt{64}=\pm 8\). Thus \(x=8\) or \(x=-8\).
Detailed Explanation
Problem
Solve the equation
\(x^{2} = 64\)
Step-by-step solution
-
Recognize the equation. We are given the quadratic equation
\(x^{2} = 64\).
-
Bring all terms to one side (optional, useful for factoring):
\(x^{2} – 64 = 0\).
This expresses the equation in the standard form “something equals zero”, which allows using the zero-product property after factoring.
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Factor the difference of squares. Use the identity \(a^{2}-b^{2}=(a-b)(a+b)\). With \(a=x\) and \(b=8\) we get
\(x^{2}-64 = (x-8)(x+8)\).
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Apply the zero-product property: if a product of two real numbers is zero, then at least one factor is zero. Thus
\((x-8)(x+8)=0\)
implies either
\(x-8=0\)
or
\(x+8=0\).
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Solve each linear equation:
If \(x-8=0\) then \(x=8\).
If \(x+8=0\) then \(x=-8\).
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Alternatively, use the square-root property: for a nonnegative number \(a\), the solutions of \(x^{2}=a\) are \(x=\pm\sqrt{a}\). Applying this with \(a=64\) gives
\(x=\pm\sqrt{64}=\pm 8\).
-
Check both solutions by substitution:
For \(x=8\): \(8^{2}=64\), so it satisfies the equation.
For \(x=-8\): \((-8)^{2}=64\), so it also satisfies the equation.
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Conclusion: the solutions are
\(\boxed{x=8}\) and \(\boxed{x=-8}\).
As a solution set: \(\{ -8,\, 8 \}\).
FAQs
What is the solution of \(x^2=64\)?
Why are there two solutions?
How do you solve it step-by-step?
Why not just \(x=8\) when using \(\sqrt{64}\)?
How does factoring work here?
Are there complex solutions?
How can I check my answers?
What about multiplicity of roots?
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