Choosing the Best Method to Solve a System of Equations

What method of solving do you think is the easiest way to solve this system?

4x + 3y = 32

x = 2y - 3

• Substitution

• Elimination

• Graphing

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Why might someone choose substitution as a good method to solve this system?

4x + 3y = 32

x = 2y - 3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which student started solving by substitution correctly?

4x + 3y = 32

x = 2y - 3

• Student A:

  4x+3(x-3)=32

• Student B:

  4(2y-3)+3y=32

• Student C:

  4x+3y=2y-3

• Student D:

  4x+3(2x-3)=32

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which student distributed correctly?

4(2y-3) + 3y = 32

• Student A:

  8y - 3 + 3y = 32

• Student B:

  6y + 1 + 3y = 32

• Student C:

  8y + 12 + 3y = 32

• Student D:

  8y - 12 + 3y = 32

Tags

CCSS.6.EE.A.3

What is the solution to this system?

4x + 3y = 32

x = 2y - 3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What would be easiest method to solve this system?

5x + 3y = 9

7x - 2y = 25

• Substitution

• Elimination

• Graphing

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Why might someone say that elimination is the easiest way to solve this system of equations?

5x + 3y = 9

7x - 2y = 25

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Multiply one or both equations so that the y-terms will eliminate.

5x + 3y = 9

7x - 2y = 25

What is the solution to the given system of equations?

5x + 3y = 9

7x - 2y = 25

Tags

CCSS.HSA.REI.C.9

Why might someone choose substitution as an easy method to solve this system?

y = 17 - x

y = 3x + 5

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6