From (x+y=15) and (y=6), what is (x)?
Answer and explanation
Correct answer: \(x=9\)
The second equation gives \(y=6\). Substituting it into \(x+y=15\) gives \(x+6=15\). Subtracting 6 from both sides gives \(x=9\), so option C is correct. If \(x=8\), the sum would be 14, not 15. Exam tip: verify the obtained value in the original equation.
Frequently asked questions
What is the correct answer to this question?
\(x=9\)
Why is this the correct answer?
The second equation gives \(y=6\). Substituting it into \(x+y=15\) gives \(x+6=15\). Subtracting 6 from both sides gives \(x=9\), so option C is correct. If \(x=8\), the sum would be 14, not 15. Exam tip: verify the obtained value in the original equation.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Pair of Linear Equations in Two Variables. Topic: Algebraic methods: Substitution method and Elimination method..
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