Chapter 8.4, Problem 9MCQ

To determine

To find the sum or difference.

Answer to Problem 9MCQ

  $3n^3+n^2-4n+15$

Explanation of Solution

Given:

Expression: $(3n^3-2n+7)+(n^2-2n+8)$

Concept used:

To find the sum or difference of polynomial,

1. Write the polynomial in standard form.
2. Rearrange the like terms together and add or subtract.

Calculation:

Applying the above concept,

The given expression is in a standard form.

So, Rearrange the like terms and add.

  $\begin{array}{l}\Rightarrow (3n^3-2n+7)+(n^2-2n+8)\\ \Rightarrow 3n^3+n^2-(2n+2n)+(7+8)\\ \Rightarrow 3n^3+n^2-4n+15\end{array}$

Conclusion:

Therefore, the sum is $3n^3+n^2-4n+15.$