Solving pairs of linear equations in two variables

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

The equation of two lines are 2x - 3y = 12 and x = 4y + 1.

What is the value of x in the solution for this system of equations?

• 2

• 9

• -2

• -9

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

3x+2y=0

y=1/2x-1

• (4/5,3/4)

• (1/2,-3/4)

• No solution

• (-1,2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is a system of equations?

• two equations with two known variables

• two equations with two unknown variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by substitution

x+y=5

x=4

• (4,1)

• (3,2)

• (1,1)

• (9,2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

y=6x+21

y=4x+57

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the value of y, after you substituted x=2 into the TOP equation?

2x + 2y = -2

3x - 2y =12

• -3

• 3

• 2

• -2

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

• (5, -3)

• (3, 5)

• (-5, -3)

• (-3, -5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve:

4x+9y=28

-4x-y=-28

• (-7,0)

• (6,0)

• (-6,0)

• (7,0)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

x - 3y = -13
4x + 2y = 4

• (1, 4)

• (-1, -4)

• (-1, 4)

• (1, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6