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If (a=-2) and (b=3), what is the value of (a^2+2b)?
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Answer and explanation
Correct answer: 10
On substitution, a² + 2b = (-2)² + 2(3) = 4 + 6 = 10. Therefore, the correct answer is 10. The option 8 may result from incorrectly adding only 2 instead of calculating 2b. Exam tip: Always use brackets when squaring a negative number; (-2)² equals 4, not -4.
Frequently asked questions
What is the correct answer to this question?
10
Why is this the correct answer?
On substitution, a² + 2b = (-2)² + 2(3) = 4 + 6 = 10. Therefore, the correct answer is 10. The option 8 may result from incorrectly adding only 2 instead of calculating 2b. Exam tip: Always use brackets when squaring a negative number; (-2)² equals 4, not -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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