Solve by substitution -- Prework

y = x - 9 
y = -9

• 0, -9
• -1, 2
• -18, -9
• -81, -3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = x + 6
y = 3

• -3,3
• -9,3
• -18,2
• 21,0

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = -x - 5
y = 3

• 8,1
• 2,3
• -2,2
• -8,3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = 5x - 4
y = x

• 0,1
• 1,1
• -1,2
• 2,3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = x + 20
y = 6x

• 4,24
• 0,24
• -4,21
• 26,0

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = -x - 10
y = 4x

• 2,8
• -1,-8
• -2,-8
• 0,8

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y = x + 24
y = -7x

• -3,21
• 3,21
• 2,21
• -2,0

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

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

Solve the system by substitution.
 
5x + 4y= −14
y =  −7x  −  15 

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

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

x + 2y = 2
x = -4y + 2

• (-3, 0)
• (0, 2)
• (-3, -2)
• (2, 0)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6