1 / 6

8-2 Substitution

8-2 Substitution. 9P9: Solve 2X2 systems by substitution. Find the solution by substitution. Steps 1 Solve 1 of equations for x or y 2 Substitute into other equation 3 Solve for other variable 4 Use answer to find original variable 5 Write answer as ordered pair 6 Check.

jtrinidad
Download Presentation

8-2 Substitution

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. 8-2 Substitution 9P9: Solve 2X2 systems by substitution

  2. Find the solution by substitution Steps 1 Solve 1 of equations for x or y 2 Substitute into other equation 3 Solve for other variable 4 Use answer to find original variable 5 Write answer as ordered pair 6 Check

  3. Ex1:Solve by Substitution • x + y = 6 and x = y + 2 1) Done (eqn 2 solved for x) 2) Substitute 3) Solve 4) Find x: x = y +2 so x = 2 + 2 or x =4 5) Write solution (4,2) 6) Check 4+2 =6 yes and 4 = 2 +2 yes (y+2)+y =6 2y +2 =6 2y=4 y=2

  4. Example 2: 4x-y =5 and 2x +y =10 1) Which letter is easiest to solve for? y 4x - y =5 and 2x +y =10 y = 10 - 2x 2) Substitute 4x-(10-2x)=5 3) Solve 4x-10 +2x = 5 6x -10 = 5 6x=15 4) Find y: so y =10-5 y=5 5) ( 5/2,5) is the solution

  5. Problem SolvingTranslate to a system then solve The sum of two numbers is 82. One number is 12 more than the other • N1: x • N2: y x + y =82 and y = x +12 S1) #2 already solved for y S2) x +(x+12) =82 S3) 2x +12 = 82 2x =70 x =35 S4) 35 +12 =y 47 =y S5) The numbers are 35 and 47

  6. Assignment • 8-2/365-366/11-29 o, 36-46e,47

More Related