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If (x=-2), what is the value of (x^2+3x+1)?
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Answer and explanation
Correct answer: -1
Given x=-2, substitute it into the expression: x^2+3x+1=(-2)^2+3(-2)+1=4-6+1=-1. Therefore, the correct value is -1. The option 1 may result from incorrectly taking 3x as +6. Exam tip: always use brackets while squaring a negative number, for example, (-2)^2=4.
Frequently asked questions
What is the correct answer to this question?
-1
Why is this the correct answer?
Given x=-2, substitute it into the expression: x^2+3x+1=(-2)^2+3(-2)+1=4-6+1=-1. Therefore, the correct value is -1. The option 1 may result from incorrectly taking 3x as +6. Exam tip: always use brackets while squaring a negative number, for example, (-2)^2=4.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Algebraic expressions.
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