What are the solutions of the equation \(8x^2=72\)?
Answer and explanation
Correct answer: \(x=\pm3\)
Dividing both sides by 8 gives \(x^2=9\). Therefore, \(x=\pm\sqrt{9}=\pm3\), so both \(x=3\) and \(x=-3\) are solutions. Writing only \(x=3\) or only \(x=-3\) is incomplete. Exam tip: remember to include both positive and negative values when taking the square root of a positive number.
Frequently asked questions
What is the correct answer to this question?
\(x=\pm3\)
Why is this the correct answer?
Dividing both sides by 8 gives \(x^2=9\). Therefore, \(x=\pm\sqrt{9}=\pm3\), so both \(x=3\) and \(x=-3\) are solutions. Writing only \(x=3\) or only \(x=-3\) is incomplete. Exam tip: remember to include both positive and negative values when taking the square root of a positive number.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Methods of Solving Quadratic Equations.
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