Pick the Method Elimination, Substitution

What is the best method to use?

2x − 3y = −1

y =x − 1

• Graphing

• Substitution because a variable is defined

• Elimination because the equations are in standard form.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the best method to use?

4x + 8y = 20

−4x + 2y = −30

• Graphing

• Substitution because a variable is defined

• Elimination because the equations are in standard form

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve for x and y
3x + 2y = 16
7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What should you multiply the TOP equation by so that the x's will cancel out?
2x - 5y = 10
4x + 15y = -10

• -2

• 2

• 3

• -3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In the Worked Example, only one equation needs to be rewritten to solve using the elimination method. Why?

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

what is the variable that willl be "eliminated"?

-5x +4y = -11

5x + 4y = -14

• x variable

• y variables

• both variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve for x and y. Show all work for credit. 3x + 2y = 16 7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the best method to use?

y = −3x + 5

5x − 4y = −3

• Graphing

• Substitution because a variable is defined

• Elimination because the equations are in standard form

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the proper set up to solve the equation?

• -7(11) -2y = -13

• -7(2y +11)-2y = -13

• -7x -2(11) =-13

• -7x - 2(2y+11)= -13

Tags

CCSS.8.EE.C.7B

What variable do you eliminate, and what do you multiply the equation(s) by?

• You eliminate x, and multiply the top equation by -2

• You eliminate y, and multiply the top equation by 7

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6