Adding and Subtracting Polynomials

• The root poly means many: polygon-many sides is another example we have seen.

• A polynomial is a mathematical expression with many terms

This isn't too important to memorize, but we will use some of this vocabulary such as binomial and trinomial in the future.

The degree is the highest exponent in the polynomial.

• Step 1: Distribute the "1s" to eliminate the parentheses.

• Step 2: Combine like terms

  • like terms have the same variables and same powers

    • 2x² and -5x² are like terms

    • -3x⁴ and -3x⁷ are NOT like terms

    • -6xy² and 13xy² are like terms

    • -4x²y and 10xy² are NOT like terms

• Since the number in front of both sets of parentheses is 1, this eliminates the parentheses

  • The parentheses mean nothing when the sign between them is addition.

    • -7.1x²-180x+5800+21x²-140x+1900

• Combine like terms

  • 13.9x²-320x+7700

• Step 1: Notice there is a -1 in front of the 2nd set of parentheses. This changes the signs of the second polynomial. *Distribute the negative/subtraction sign into the second set of parentheses.

  • x³-3x²+5x-7x³-5x²+12

• Step 2: Combine Like Terms

  • -6x³-8x²+5x+12