Which of the following is the factorised form of \\(x^2 + x - 12 = 0\\)?
Answer and explanation
Correct answer: \\((x+4)(x-3)=0\\)
Expand \\((x+4)(x-3)\\): \\(x^2 -3x +4x -12 = x^2 + x -12\\), so it matches the given quadratic. Closest distractor B expands to \\((x-4)(x+3)= x^2 - x -12\\), which has the middle term \\(-x\\) (wrong sign). Options C and D expand to \\(x^2+7x+12\\) and \\(x^2-7x+12\\) respectively, so they do not match. Exam tip: find two numbers whose product is \\-12\\ and sum is \\+1\\ (here 4 and -3).
Frequently asked questions
What is the correct answer to this question?
\\((x+4)(x-3)=0\\)
Why is this the correct answer?
Expand \\((x+4)(x-3)\\): \\(x^2 -3x +4x -12 = x^2 + x -12\\), so it matches the given quadratic. Closest distractor B expands to \\((x-4)(x+3)= x^2 - x -12\\), which has the middle term \\(-x\\) (wrong sign). Options C and D expand to \\(x^2+7x+12\\) and \\(x^2-7x+12\\) respectively, so they do not match. Exam tip: find two numbers whose product is \\-12\\ and sum is \\+1\\ (here 4 and -3).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Introduction to Quadratic Equations.
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