If (2x+y=11) and (2x-y=5), what will be the value of (x)?
Answer and explanation
Correct answer: \(x=4\)
On adding the two equations, \(y\) and \(-y\) cancel: \((2x+y)+(2x-y)=11+5\), so \(4x=16\). Hence, \(x=4\). The nearby option \(x=3\) would give \(4x=12\), not the required \(4x=16\). Exam tip: add the equations when a variable has opposite coefficients so that it is eliminated.
Frequently asked questions
What is the correct answer to this question?
\(x=4\)
Why is this the correct answer?
On adding the two equations, \(y\) and \(-y\) cancel: \((2x+y)+(2x-y)=11+5\), so \(4x=16\). Hence, \(x=4\). The nearby option \(x=3\) would give \(4x=12\), not the required \(4x=16\). Exam tip: add the equations when a variable has opposite coefficients so that it is eliminated.
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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