Approach to find whether an expression is EVEN or ODD
It is a 3 step process:
1. \(n^x\) has the same Even and Odd nature as a \(n\) itself so always ignore the power it doesn't matter whether power \(x\) = 2, 3, 100 or so no provided that x is a positive integer.
Always ignore/delete the exponent provided that exponent is a positive integer.
2. Ignore/delete the term which u know is an Even number.
3. if the coefficient of n is odd integer, just ignore the coefficient and write it as n only for simplicity, if the coefficient of n is Even, ignore/delete the complete term as it is Even
A. \(n^2-10n+21\)
Delete 10n as it is Even, and ignore exponent 2, the expression is n +21, this can be even or odd when n is odd or even, Not the right answer
B. \(n^2-2n-24\)
Delete 2n and 24 as these are Even, and ignore the exponent, the expression is n , which can be even or odd. Not the right answer
C. \(n^2+8n+7\)
Delete 8n as it is Even, and ignore the exponent, the expression is n+7, this can be even or odd when n is odd or even, Not the right answer
D. \(n^2+11n+18\)
Delete 18 as it is Even, and ignore the exponent, also ignore the odd coefficient 11, the expression is n+n = 2n , which must be even as n is an integer
RIGHT ANSWERE. \(n^2-4n-60\)
Delete 4n and 60 as these are Even, and ignore the exponent, the expression is n , which can be even or odd. Not the right answer