Solving (7x+11y=103) and (14x-11y=23), what is the value of (x)?
Answer and explanation
Correct answer: 6
Adding the two equations eliminates the y-terms because their coefficients are opposites: (7x+11y)+(14x-11y)=103+23, giving 21x=126. Hence, x=126/21=6, so option C is correct. Exam tip: look first for equal and opposite coefficients, as they allow immediate elimination of one variable.
Frequently asked questions
What is the correct answer to this question?
6
Why is this the correct answer?
Adding the two equations eliminates the y-terms because their coefficients are opposites: (7x+11y)+(14x-11y)=103+23, giving 21x=126. Hence, x=126/21=6, so option C is correct. Exam tip: look first for equal and opposite coefficients, as they allow immediate elimination of one variable.
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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