Solving Systems of Equations

What is the best method do you use?

y = 6x − 11

−2x − 3y = −7

• Graphing

• Substitution because a variable is defined

• Elimination because both equations are in standard form.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the best method to use?

−4x − 2y = −12

4x + 8y = −24

• 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 variable do you eliminate?

4x + 8y = 20

−4x + 2y = −30

• X because they have opposite signs

• Y because they have opposite signs

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the proper set up to solve the equation?

-7x -2y= -13

x = 2y+11

• -7(11) -2y = -13

• -7(2y +11)-2y = -13

• -7x -2(11) =-13

• -7x - 2(2y+11)= -13

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the proper way to set up the equation to begin solving?

y = 6x − 11

−2x − 3y = −7

• -2(-11) -3y= -7

• -2(6x-11) -3y = -7

• -2x -3(11) = -7

• -2x - 3(6x-11)= -7

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

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

5x + y = 9

10x − 7y = −18

• 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

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

Solve the system given:
3x - y = 7
2x + y = 3

• (-1,2)
• (5,4)
• (4,5)
• (2,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system:

x+ 3y = 9

2x+ y = −2

• (3,2)

• (-2, 2)

• (3, -4)

• (-3, 4)

• (0.5, -3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Parallel Lines never intersect because...

• they have the same slopes. 
• they have the same y-intercept.
• they have different slopes.
• they have different y-intercepts. 

Tags

CCSS.HSF-IF.C.7A