Elimination Method and Substitution Method

Elimination Method and Substitution Method

Multiple Choice

Are both equations in STANDARD FORM?

• yes

• no

Multiple Choice

Is there a zero pair?

• yes

• no

Multiple Choice

Combine the two equations.

• 6y = -36

• 6x = -36

• 8x + 6y = -36

• -8x - 6y = -36

Multiple Choice

6y = - 36

Solve for y

• y = - 4

• y = 5

• y = -6

Multiple Choice

If y = -6

Substitute into top equation for y

• -4(-6) - 2(-6) = -12

• -4(-6) - 2y = -12

• -4x - 2(-6) = -12

Multiple Choice

-4x - 2(-6) = -12

Simplify

• -4x - 12 = -12

• 12 = -12

• -4x +12 = -12

Multiple Choice

-4x +12 = -12

Solve for x

• x = 2

• x = 6

• x = 4

Multiple Choice

x = 6

y = -6

Write this as an ordered pair

• (-6, 6)

• (6, -6)

• 6, -6

• x= 6 y = -6

Multiple Choice

Are both equations in Standard Form

• yes

• no

Multiple Choice

Is there a zero pair

• yes

• no

Multiple Choice

What can we multiply the top equation by to make a zero pair with the x coefficients?

• -2

• -3

• 3

• 2

Multiple Choice

Multiply the top equation by -3.

• 9x - 21y = 48

• -9x + 21y = 48

• 9x - 21y = -48

Multiple Choice

9x - 21y = 48

-9x + 5y = 16

Combine the equations

• -16y = 64

• 18x - 16y = 64

• 18x = 64

Multiple Choice

Are both these equations in STANDARD FORM

• yes

• no

When an equation is solved for x or y: use the SUBSTITUTION METHOD

Multiple Choice

replace the y in the bottom equation with what y equals in the top equation

• -2(6x-11) -3y = -7

• -2x -3(6x-11) = -7

• -2(6x - 11) -3(6x-11) = -7

Poll

How are you feeling on understanding the elimination method and substitution method

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• Starting to understand

• Getting close to perfect

• I can teach it