Solving by Substitution

What does Substitution mean?

• To submerge in water

• The action of replacing

• To add a bunch of numbers together

• To stand up for the Constitution

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which choice shows substitution correctly?

y = 2x + 3

3x + 2y = 20

• 3x + (2x + 3) = 20

• 3x + 2y(2x + 3) = 20

• 3x + 2 (2x + 3) = 20

• y + 2x + 3 = 20

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = 2x + 5
-4x + y = 9

• (-2, 1)
• (-2, -1)
• (2, -1)
• (2, 1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system?
8x + 4y = 12
y = -2x + 3

• (0,3)
• (3,0)
• No solution(parallel lines)
• Infinitely many solutions

Tags

CCSS.8.EE.C.8B

What is the solution to this system?
y = x + 5
4x + y = 20

• (3,8)
• (8,3)
• (0,2)
• (2,0)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations.

y = 4x + 1

3x + 2y = 13

• (1, 5)

• (5, 1)

• (0.25, 2)

• ∅

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations using substitution:
3x - y = -8
x = -2

• (2, 2)
• (-2, -14)
• (-2, 2)
• (2, 14)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve:
y = 7x + 9
2y + 2x = -18

• (5, 0)
• (9, 18)
• (-2, -5)
• (1, 16)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

3(x-6)+2x=22

• x=8
• x=2
• x=18
• x=3

Tags

CCSS.8.EE.C.7B

Solve by substitution method

y = 4x + 30

y = -x + 45

• (9, 37)

• (3, 42)

• (37, 9)

• (42, 3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6