Factoring and expanding polynomials Flashcards
Steps to subtracting polynomials
To subtract Polynomials, first reverse the sign of each term we are subtracting (in other words turn “+” into “-“, and “-“ into “+”), then add as usual.
Steps to add a polynomial
- Identity like terms and group together.
Example: Add (2x2 + 6y + 3xy) , (3x2 - 5xy - x) and (6xy + 5) Line them up in columns and add: 2x2 + 6y + 3xy 3x2 - 5xy - x 6xy + 5
5x2 + 6y + 4xy - x + 5
1 term x 1 term (monomial times monomial)
To multiply one term by another term, first multiply the constants, then multiply each variable together and combine the result.
Example: (2xy) (4y)= 24xy*y=8xy^2
To multiply two polynomials:
- multiply each term in one polynomial by each term in the other polynomial.
- add those answers together, and simplify if needed.
1 term × 2 terms (monomial times binomial)
Multiply the single term by each of the two terms, like this:
2x(x+3xy)= 2xx+2x3xy
= 2x^2+6x^2y
2 term × 1 terms (binomial times monomial)
Multiply each of the two terms by the single term, like this:
(x^2-x) 3y = 3x^2-3xy
2 terms × 2 terms (binomial times binomial)
Each of the two terms in the first binomial is multiplied by each of the two terms in the second binomial. That is 4 differrent multiplications.
(2x+3)(xz-a)= 2x^2z-2xa+3xz-3a
2 terms × 3 terms (binomial times trinomial)
Multiply each term in the first polynomial by each term in the second polynomial. And then combine like terms.
Example: (x + 2y)(3x − 4y + 5)
= 3x2 − 4xy + 5x + 6xy − 8y2 + 10y
= 3x2 + 2xy + 5x − 8y2 + 10y