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Exercises Expressions, exponents and radicals

Example 2 from Algebra and Trigonometry, 1.4 Polynomials

Adding Polynomials

Find the sum.

$(12 x^{2} + 9 x - 21) + (4 x^{3} + 8 x^{2} - 5 x + 20)$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution
$\begin{matrix} 4 x^{3} + (12 x^{2} + 8 x^{2}) + (9 x - 5 x) + (−21 + 20) & Combine like terms . \\ 4 x^{3} + 20 x^{2} + 4 x - 1 & Simplify . \end{matrix}$

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Find the sum.

$(2 x^{3} + 5 x^{2} - x + 1) + (2 x^{2} - 3 x - 4)$

How did it go?

PreviousIdentifying the Degree and Leading Coefficient of a Polynomial Next Subtracting Polynomials

From Algebra and Trigonometry (1st edition) by OpenStax (Rice University), section 1.4, licensed under CC BY 4.0. Original at openstax.org. We split the solution into steps; the words, numbers and figures are the book's. OpenStax doesn't endorse this site.