Using elimination, what value of (y) is obtained by subtracting (x+y=8) from (x+4y=17)?
Advertisement
Answer and explanation
Correct answer: \(y=3\)
Subtracting the second equation from the first gives \((x+4y)-(x+y)=17-8\). Thus, \(3y=9\), so \(y=3\). For example, \(y=4\) cannot satisfy both equations simultaneously. Exam tip: In elimination, subtract every term on both sides carefully to avoid sign errors.
Frequently asked questions
What is the correct answer to this question?
\(y=3\)
Why is this the correct answer?
Subtracting the second equation from the first gives \((x+4y)-(x+y)=17-8\). Thus, \(3y=9\), so \(y=3\). For example, \(y=4\) cannot satisfy both equations simultaneously. Exam tip: In elimination, subtract every term on both sides carefully to avoid sign errors.
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