In the equations (2x+y=7) and (x=2), what is the value of (y)?
Advertisement
Answer and explanation
Correct answer: \(y=3\)
Given \(x=2\), substitute it in \(2x+y=7\): \(2(2)+y=7\), or \(4+y=7\). Hence, \(y=3\). If \(y=5\), the left side becomes \(2(2)+5=9\), not 7. Exam tip: after substitution, solve the resulting simple linear equation carefully.
Frequently asked questions
What is the correct answer to this question?
\(y=3\)
Why is this the correct answer?
Given \(x=2\), substitute it in \(2x+y=7\): \(2(2)+y=7\), or \(4+y=7\). Hence, \(y=3\). If \(y=5\), the left side becomes \(2(2)+5=9\), not 7. Exam tip: after substitution, solve the resulting simple linear equation carefully.
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..
Advertisement