Adding and Subtracting Polynomials
After studying this lesson, you will be able to:
- Add and subtract polynomials.
When adding and subtracting polynomials, remember that you can
only add or subtract like terms. And, remember to add or subtract
the coefficients - the exponents do not change.
( 3y 2 + 5y - 6 ) + (7y 2 - 9 )
We are adding two polynomials so all we do is to collect like
terms. It's a good idea to put the answer in descending order as
Adding like terms the answer will be: 10y 2 + 5y -
( 4x 2 -3y 2 + 5xy ) - ( 8xy + 6x 2
+ 3y 2 )
We are subtracting two polynomials so first we "add the
opposite" in the second polynomial.
This will give us: ( 4x 2 -3y 2 + 5xy )
+ ( - 8xy - 6x 2 - 3y 2 )
Now, we add like terms, beginning with the highest exponent so
that our answer will be in descending order. Adding like terms
the answer will be: -2x 2 - 3xy - 6y 2