Solving a system of equations (best method)

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?

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

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

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

The ordered pair that satisfies BOTH equations in the system is called the _____________________

• system of equations
• function
• graph
• solution 

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

solve for x and y
5x + 3y = 7
y = 4

• (4,1)
• (4,-1)
• (1,4)
• (-1,4)

Tags

CCSS.HSA.REI.C.9

Solve the system:
x + y = 19
y = 3x - 1

• (14, 5)
• (11, 8)
• (5, 14)
• (8, 11)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system:
3x + y = 19
2x - y = 6

• (5, 14)
• (4, 5)
• (5, 4)
• (14, 5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system:
2x - 5y = 12
y = -2

• y = -2
• (11, -2)
• (1, -2)
• no solution

Tags

CCSS.HSA.REI.C.9