Example 4: Adding and subtracting polynomials | Algebra I | Khan Academy - By Khan Academy
| 00:0-1 | were asked to simplify this huge long expression here . | |
| 00:03 | Extra third plus three X minus six that's in parentheses | |
| 00:06 | , plus negative two X squared plus X minus two | |
| 00:10 | and then minus the quantity three X minus four . | |
| 00:12 | So a good place to start . We'll just rewrite | |
| 00:14 | this and see if we can eliminate the parentheses in | |
| 00:17 | the steps of the first to start at the beginning | |
| 00:19 | , we have the extra third right over there , | |
| 00:23 | so extra third and then plus three x under that | |
| 00:27 | pink plus three x plus three x and then we | |
| 00:32 | have a minus six minus six . And we don't | |
| 00:36 | have to put the parentheses around there that those don't | |
| 00:38 | really change anything . Plus , and we don't have | |
| 00:40 | to even write these parents do anything with these parentheses | |
| 00:42 | . We can eliminate them because there is a positive | |
| 00:44 | sign out here . We don't have to distribute anything | |
| 00:46 | . Distributing a positive sign doesn't do anything . These | |
| 00:48 | numbers . So then , Plus , we have a | |
| 00:50 | negative two x squared . So this term right here | |
| 00:54 | is negative two x squared or minus X squared , | |
| 00:57 | and then we have a plus X . We have | |
| 01:00 | a plus X plus X , Then we have a | |
| 01:05 | minus two . We have a minus two . Then | |
| 01:09 | we have a negative sign . Times this hold expressions | |
| 01:11 | were going to distribute the negative science , so it's | |
| 01:13 | a positive . Three . X is being multiplied by | |
| 01:15 | negative one , so it's really a negative three x | |
| 01:18 | so minus three x minus three X and then you | |
| 01:22 | have a negative you can imagine . This is a | |
| 01:24 | negative one implicitly out here . Negative one times negative | |
| 01:27 | . Four . That's a positive four . So plus | |
| 01:29 | four plus four Now we can combine terms of similar | |
| 01:35 | degree of the same degree . Now , first we | |
| 01:37 | have an extra third term , and I think it's | |
| 01:38 | the only third degree term here because we have X | |
| 01:41 | being raised to the third power . Let me just | |
| 01:43 | read right here . We have extra third and also | |
| 01:45 | look at our X Square terms . Looks like we | |
| 01:47 | only have one . We only have this term right | |
| 01:50 | here , so we have minus two x squared . | |
| 01:54 | And what about our X terms ? We have a | |
| 01:56 | three X plus and X minus three x again so | |
| 02:00 | that three x minus three x will cancel out and | |
| 02:03 | you're just left with an X . So plus X | |
| 02:07 | and then finally are constant terms . Negative . Six | |
| 02:10 | minus two plus four Negative . Six minus two gets | |
| 02:13 | us to negative . Eight plus four is negative . | |
| 02:17 | Four negative four and we are done . We have | |
| 02:20 | simplified the expression . Now we just have a four | |
| 02:23 | term polynomial . |
DESCRIPTION:
This video is from Khan Academy. It demonstrates the proper method of adding and subtracting polynomials
OVERVIEW:
Example 4: Adding and subtracting polynomials | Algebra I | Khan Academy is a free educational video by Khan Academy.It helps students in grades 9,10,11,12 practice the following standards HSA.APR.A.1.
This page not only allows students and teachers view Example 4: Adding and subtracting polynomials | Algebra I | Khan Academy but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.
1. HSA.APR.A.1 : Understand that polynomials form a system analogous to the integers, namely, they are closed under the operations of addition, subtraction, and multiplication; add, subtract, and multiply polynomials.
