By elimination, if (2x+y=11) is subtracted from (2x+3y=19), what is (y)?
Advertisement
Answer and explanation
Correct answer: \(y=4\)
Subtracting the second equation from the first gives \((2x+3y)-(2x+y)=19-11\). Thus, \(2y=8\), so \(y=4\). If \(y=3\), then \(2y=6\), which does not match the obtained equation \(2y=8\). Exam tip: while eliminating, subtract every term carefully and keep track of signs.
Frequently asked questions
What is the correct answer to this question?
\(y=4\)
Why is this the correct answer?
Subtracting the second equation from the first gives \((2x+3y)-(2x+y)=19-11\). Thus, \(2y=8\), so \(y=4\). If \(y=3\), then \(2y=6\), which does not match the obtained equation \(2y=8\). Exam tip: while eliminating, subtract every term carefully and keep track of signs.
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