Using elimination method on (6x+5y=39) and (4x-5y=11), what is (x)?
Answer and explanation
Correct answer: \(x=5\)
The coefficients of y are +5 and -5, so y is eliminated when the equations are added: \(6x+5y+4x-5y=39+11\). Thus, \(10x=50\), giving \(x=5\). If \(x=4\), then \(10x=40\), so it cannot satisfy the added equation. Exam tip: Before eliminating, look for terms with equal coefficients and opposite signs.
Frequently asked questions
What is the correct answer to this question?
\(x=5\)
Why is this the correct answer?
The coefficients of y are +5 and -5, so y is eliminated when the equations are added: \(6x+5y+4x-5y=39+11\). Thus, \(10x=50\), giving \(x=5\). If \(x=4\), then \(10x=40\), so it cannot satisfy the added equation. Exam tip: Before eliminating, look for terms with equal coefficients and opposite 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..
