Solving systems using substitution - Math 8

What's the first step in solving this equation for y:
2x + y = 12

• Divide everything by 2

• Add 2x + y to get 2xy

• Subtract 2x from both sides
• Subtract 12 from both sides

Tags

CCSS.6.EE.C.9

What does
"solution to a system of equations"
mean?

• It's the point where both equations equal zero
• It's the point where graphs of both equations cross the y-axis
• It's the point that solves both equations at the same time
• It's the point where graphs of both equations cross the x-axis

Tags

CCSS.8.EE.C.8B

What are the possible solutions to a system of equations?

• Either 1 or 2 points
• No more than 10
• No less than 10
• Either 0, 1, or infinitely many points

Tags

CCSS.8.EE.C.8B

Which equation is solved for a variable?

• x + y = 7

• 2x - 3y = 12

• 2y = 7x - 1

• x = 3y + 2

Tags

CCSS.HSA.CED.A.4

For the following system, what would your first step be to solve using substitution?    

 $2x-y=17$  

 $x=5$  

• 2x - 5 = 17

• 2(5) - y = 17

• 2x - y + 5 = 17

• 2x - y = 17 - 5

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

2x + y = 18
y = 8

• (5, 8)
• (-5, 8)
• (2, 8)
• (-2, 8)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = 2x + 9

x = -3

• (-3, -33)

• (-3, 8)

• (-3, 3)

• (3, -3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution. 
3x − 2y = 7 
y = 2x − 7 

• No solution 
•  (7, 7)  
•  (−7, −7)  
•  (−7, −3)  

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve:

y = 7x - 9

2x + 2y = -18

• (5, 0)

• (9, 18)

• (-2, -5)

• (0, -9)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

6x = y

3y - 4x = 42

• (3, 18)

• (8, 2)

• (2, 8)

• (1, 6)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6