If (t=3), what is the value of (2t^4-5t^3+t^2)?
Answer and explanation
Correct answer: 36
Substituting \(t=3\), we get \(2t^4-5t^3+t^2=2(3^4)-5(3^3)+3^2\). Since \(3^4=81\), \(3^3=27\), and \(3^2=9\), the value is \(2\times81-5\times27+9=162-135+9=36\). Therefore, \(36\) is correct. A value such as \(18\) can result from incorrectly evaluating powers or coefficients. Exam tip: calculate powers first, then perform multiplication and subtraction.
Frequently asked questions
What is the correct answer to this question?
36
Why is this the correct answer?
Substituting \(t=3\), we get \(2t^4-5t^3+t^2=2(3^4)-5(3^3)+3^2\). Since \(3^4=81\), \(3^3=27\), and \(3^2=9\), the value is \(2\times81-5\times27+9=162-135+9=36\). Therefore, \(36\) is correct. A value such as \(18\) can result from incorrectly evaluating powers or coefficients. Exam tip: calculate powers first, then perform multiplication and subtraction.
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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