Adding Polynomials
Part of the Exponents & Polynomials section of Coddy's Algebra journey. Lesson 42 of 64.
To add polynomials, remove the parentheses and combine the like terms. When a plus sign comes before the parentheses, every term inside keeps its sign. In 3x^2 + 2x + (x^2 - 5x), removing the parentheses gives 3x^2 + 2x + x^2 - 5x.
Now group the terms by degree and add their coefficients. The squared terms give 3x^2 + x^2 = 4x^2. The x terms give 2x - 5x = -3x. The sum is 4x^2 - 3x.
After removing the parentheses, group the terms that have the same variable and the same exponent. Add their coefficients to get the simplified polynomial. In the example, 3x^2 and x^2 are like terms, and so are 2x and -5x. The terms x^2 and x are not like terms, so they stay separate.
Challenge
MediumAdd the polynomials 2x^2 + 4x + (3x^2 - x).
Try it yourself
Simplify the expression
This lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Exponents & Polynomials
1What a Power Is
Repeated MultiplicationSquares and CubesPowers of Negative NumbersWhere the Minus LivesRecap: First Powers4Power of a Power
A Power Raised AgainWhy Exponents MultiplyProduct Rule or Power Rule?The Rule in LettersRecap: Power of a Power2The Product Rule
Multiplying Same BasesWith CoefficientsMore Than Two FactorsThe Rule in LettersRecap: The Product Rule5Product and Quotient Powers
Every Factor Gets the PowerWith a Number InsideA Power of a QuotientAll Three Rules TogetherRecap: Products and Quotients8What a Polynomial Is
Terms with PowersThe DegreeLike Terms, Only StrongerRecap: Meet the Polynomials11Dividing by a Monomial
Splitting the FractionDividing by a Variable TermBigger SplitsCancel with CareRecap: Dividing3The Quotient Rule
Dividing Same BasesWhy Exponents SubtractWith CoefficientsThe Rule in LettersRecap: The Quotient Rule6Zero and Negative Exponents
The Zero ExponentZero at WorkNegative Means ReciprocalWriting Without NegativesPowers of TenRecap: Zero and Negative9Adding and Subtracting
Adding PolynomialsSubtracting PolynomialsThe Minus Reaches EverythingPerimeter as a PolynomialRecap: Add and Subtract