Solving Systems of Equations by Substitution

y = -6x + 5
-2x + y = 5

• (-3, -6)
• (-6, 3)
• (0, 5)
• (-3, 5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

6x + y = -1
y = -3x - 4

• (3, 1)
• (1, 7)
• (-3, 1)
• (1, -7)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = -3x + 11
5x + y = 21

• (1, -5)
• (1, 5)
• (-4, 5)
• (5, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = -2x + 18
y = 8

• (5, 8)
• (-5, 8)
• (2, 8)
• (-2, 8)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve:
y = 2x -11
-3y = -6x -15

• (-1.5,-4)
• (1.5,4)
• No solution (parallel lines)
• Infinitely many solutions

Tags

CCSS.8.EE.C.8B

What is the first step in solving a system by Substitution?

• Make sure both equations are in standard form.
• Make sure at least one equation is solved for one variable.
• Make sure both equations are in slope-intercept form.
• Make sure both equations can be solved.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• (1,-1)

• Infinitely many solutions

• (3,4)

• No solution

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• Infinitely many solutions

• (3,-7)
  

• (5,9)

• No solution

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• (-1,1)

• No solution

• (10,6)

• Infinitely many solutions

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• (6,-2)

• (4,-8)

• Infinitely many solutions

• No solution

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6