1 / 12

140 likes | 368 Views

Solving Systems of Equations using Substitution * Best method when one variable is already solved for or if a variable has a coefficient of 1. Solving Systems of Equations using Substitution. Steps: 1. Solve One equation for One variable.( y = ; x = ; a =)

Download Presentation
## Solving Systems of Equations using 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

**Solving Systems of Equations using Substitution* Best method**when one variable is already solved for or if a variable has a coefficient of 1.**Solving Systems of Equations using Substitution**Steps: 1. Solve One equation for One variable.( y= ; x= ; a=) 2. Substitute equation from step one into other equation. (Get an equation with only one variable.) 3. Solve for the variable in step 2. 4. Go back and use the found variable in step 3 to find second variable. 5. Check the solution in both equations of the system. WHAT DO WE DO???? CLICK TO SEE AN EXAMPLE**Ex. 1: Solve the system of equations.**y= 4x 3x+y=-21 STEP1: y=4x (already solved for y) STEP 2: Substitute for y in the second equation 3x + y = -21 and it becomes: 3x +4x =-21**GIVEN EXAMPLE:**y= 4x 3x+y=-21 STEP 3: Solve for the variable. 3x + 4x=-21 7x=-21 x=-3**GIVEN EXAMPLE:**y= 4x 3x+y=-21 STEP 4: Solve for the other variable. Use x=-3 and y=4x. y=4x and x = -3 therefore: y=4(-3) or y = -12 Solution to the system is (-3,-12).**GIVEN EXAMPLE:**y= 4x 3x+y=-21 Check solution. ( -3,-12) y=4x -12=4(-3) -12=-12 3x+y=-21 3(-3)+(-12)=-21 -9+(-12)=-21 -21=-21**Solving Systems of Equations using Substitution**Steps: 1. Solve One equation for One variable.( y= ; x= ; a=) 2. Substitute equation from step one into other equation. (Get an equation with only one variable.) 3. Solve for the first variable. 4. Go back and use the found variable in step 3 to find second variable. 5. Check the solution in both equations of the system. QUESTIONS?**GIVEN EXAMPLE:**x + y=10 5x - y=2 STEP1: Solve for y. x + y = 10 y = -x +10 STEP 2: Substitute for y in the second equation 5x - y= 2 and it becomes: 5x - (-x+10) = 2**GIVEN EXAMPLE:**x + y=10 5x - y=2 STEP 3: Solve for the variable. 5x-(-x+10)=2 5x+x-10=2 6x-10=2 6x=12 x=2**GIVEN EXAMPLE:**x + y=10 5x - y=2 STEP 4: Solve for the other variable. Use x=2 and x+y=10. x=2 and x+y = 10 therefore: 2+y=10 and y = 8 Solution to the system is (2,8).**GIVEN EXAMPLE:**x + y=10 5x - y=2 Check solution. (2,8) 5x-y=2 5(2)-(8)=2 10-8=2 2=2 x + y=10 2+8=10 10=10

More Related