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### Course: Integrated math 3>Unit 1

Lesson 3: Adding and subtracting polynomials

# Subtracting polynomials

Master the art of adding and subtracting polynomials! Learn how to distribute negative signs across terms, combine like terms, and simplify expressions. This skill is key to understanding algebra and making math easier. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• at why are we adding negative 1 times 3x
• because you are going to have to distribute the negative one to all of the 3x square + x - 9
• why it is multiplyed by -1?
• Because negative sign is equal to -1 and he is distributing it.
• I know Sal Khan doesn't mention this, but how would we go about solving for x in (16x+14) - (3x² + x - 9)?
• What you've written is just an expression, not an equation. You can't solve for x because there's nothing to solve.

You can simplify the expression, but it will still have different values for different values of x.
• why do we have to include the negative 1 in this problem, but not in others where you subtract polynomials.
• I believe the -1 is simply to emphasize the fact that you need to distribute the negative sign throughout the polynomial.

Either way, at the end (when done correctly), putting a negative 1 or a negative sign can be used interchangably.
• Is this really Algebra 2? At school I did this in Algebra 1. Is this a review/preview or something?
• Same I'm homeschooled and I did this last year I feel like 9th grade and 10th grade re the same I'm learning the same stuff I might just skip 10th or better yet get my G.E.D
(1 vote)
• using division algorithm divide 6x^3+13x^2+x-2 by 2x+1 and find the quotient and remainder
• Just divide! The quotient would be 3x^2 + 5x - 2 and there is no remainder.
Hope this helps! If you have any questions or need help, please ask! :)
• where did you get the -1.
• Remember X and 1X are the same thing. Thus -X and -1X are the same thing. The "-" in front of the parentheses is just like the "-" in front of "-x". It can be changed to -1, which is what Sal did in the video.

Hope this helps.
• What is the Foil Method?