Systems of Equations by Substitution

The first step in solving using the substitution method is __________.

• get x by itself
• get y by itself
• get either variable by itself
• add the equations together

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

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

The equations of two lines are:
 2x-y=4 and y=-2x+8.
What is the value of x in the solution for this system?

• x=8
• x=3
• x=11
• x=5

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the following system using the substitution strategy.
 -7x - 2y = -13
X = 2y + 11

• (5,6)
• (3,-4)
• (-4, 4)
• (-3, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In 3x + 2y = 10    and    x - 5y = 18, which variable should you isolate first?

• The x in the first equation
• The y in the first equation
• The x in the first equation
• The x in the second equation

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations by elimination.
-x + y = -13
-8x - 4y = -8 

• (5, 8)
• (5, -8)
• (-5, -18)
• (-5, 8)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Define the variables, set up a system of equations and solve using the substitution method.

• 4 cm by 13 cm
• 6 cm by 11 cm
• 9 cm by 5 cm
• 8 cm by 7 cm

Tags

CCSS.8.EE.C.8C

Some students want to order shirts with their school logo. One company charges $9.65 per shirt plus a setup fee of $43. Another company charges $8.40 per shirt plus a $58 fee. Which equation represents the number of shirts when both companies charge the same amount?

• y = 9.65 + x

  y = 8.40 + x

• y = 9.65x + 43

  y = 8.40x + 58

• y = 9.65x

  y = 8.40x

• y = 9.65x - 43

  y = 8.40x - 58

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.CED.A.2

CCSS.HSA.REI.B.3

CCSS.HSA.REI.D.11

CCSS.HSA.SSE.A.1

For the following equations, it would be easier to change the ​ (a)   variable into opposites by multiplying by ​ (b)   ​ .

2x + 3y = 12

4x - 7y = - 54

• x
• -2
• y
• 2
• 7
• 3