If one root of the quadratic equation \(x^2-(m+7)x+7m=0\) is 7, what is the other root?
Answer and explanation
Correct answer: \(m\)
For a quadratic \(ax^2+bx+c=0\), the product of roots equals \(c/a\). Here \(a=1\) and \(c=7m\), so the product is \(7m\). Given one root is 7, the other root is \(\dfrac{7m}{7}=m\). Check with the sum: sum = \(-b/a\) = \(m+7\), which matches \(7+m\). The closest distractor (option B: \(7m\)) confuses the product with a root. Exam tip: always apply sum = \(-b/a\) and product = \(c/a\), and watch the signs of coefficients.
Frequently asked questions
What is the correct answer to this question?
\(m\)
Why is this the correct answer?
For a quadratic \(ax^2+bx+c=0\), the product of roots equals \(c/a\). Here \(a=1\) and \(c=7m\), so the product is \(7m\). Given one root is 7, the other root is \(\dfrac{7m}{7}=m\). Check with the sum: sum = \(-b/a\) = \(m+7\), which matches \(7+m\). The closest distractor (option B: \(7m\)) confuses the product with a root. Exam tip: always apply sum = \(-b/a\) and product = \(c/a\), and watch the signs of coefficients.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Introduction to Quadratic Equations.
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