1 / 13

Simultaneous equations

Simultaneous equations. Yes, I know we’ve done this but you were a little ropey last week. 4 ways of solving them. Pros If you guess well, then easy to solve. Cons Hard to show your working. Only works for really simple ones. Can take a lot of time. 1 Guessing the answers. Pros

gavin
Download Presentation

Simultaneous equations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Simultaneous equations Yes, I know we’ve done this but you were a little ropey last week.

  2. 4 ways of solving them

  3. Pros If you guess well, then easy to solve. Cons Hard to show your working. Only works for really simple ones. Can take a lot of time. 1 Guessing the answers.

  4. Pros Works for all but the most complicated equations( A – level). Will give exact answer. Cons Need to show all working and work carefully. May need to multiply equations first 2 By adding/subtracting equations(traditional method)

  5. Pros Will work every time Works for families of equations Cons Not always accurate Time consuming Long-winded, lots of room for mistakes to creep in. 3 Graphically

  6. Pros Can be quickest way Best way for complicated equations e.g.. powers Cons Not suitable for all equations More likely you are looking at A – level paper. 4 Substitution

  7. Traditional approach

  8. 2x + 2y = 83x – y = 16 Number equations 2x + 2y = 8 3x – y = 16 Make ‘y’s the same by multiplying x 2 6x – 2y = 32 1 2 2 3

  9. 2x + 2y = 83x – y = 16 2x + 2y = 8 Same no. of y’s in 3x – y = 16 6x – 2y = 32 DIFFERENT signs so ADD + 8x = 40 x = 5 1 1 3 2 3 1 3

  10. 2x + 2y = 83x – y = 16 2x + 2y = 8 3x – y = 16 Substitute x = 5 in (easiest) 2 x 5 + 2y = 8 10 + 2y = 8 2y = -2 y = -1 1 2 1

  11. Almost there

  12. 2x + 2y = 83x – y = 16 We have x = 5 and y = -1 so now we CHECK IT Check inbecause we haven’t used that yet (3 x 5) – (-1) = 15 - - 1 = 15 + 1 = 16 2

  13. And finally….. Don’t forget to write your answers down clearly x = 5 and y = -1

More Related