Solving Systems of Equations

What is the best method do you use?

y = 6x − 11

−2x − 3y = −7

• Graphing

• Substitution because a variable is defined

• Elimination because both equations are in standard form.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Alexandra finds that she can give 3 haircuts and 2 hair dyes in 315 minutes. Giving 2 haircuts and 4 hair dyes takes 450 minutes.  Which system of equations represents the situation?

• 3x + 2y = 315
  2x + 4y = 450
• 3x + 2y = 450
  2x + 4y = 315
• 2x + 2y = 315
  3x + 4y = 450

Tags

CCSS.HSA.CED.A.3

Solve the system given:
3x - y = 7
2x + y = 3

• (-1,2)
• (5,4)
• (4,5)
• (2,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve for x and y
5x + 3y = 7
y = 4

• (4,1)
• (4,-1)
• (1,4)
• (-1,4)

Tags

CCSS.HSA.REI.C.9

Solve for x and y
2x − 3y = −1
 y = x − 1

• (-2,-3)
• (0,-1)
• (3,4)
• (4,3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination:
4x+4y=4

3x+4y=10

• (7,-6)
• (-6,7)
• (6,7)
• (7,6)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination 
2x+9y= -7 
6x-3y= 9 

• (-1, -1) 
• (2,-1)
• (1,1)
• (1,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Last season two running backs on the Steelers football team rushed a combined total of 1550 yards.  One rushed 4 times as many yards as the other.  Let x and y represent the number of yards each individual player rushed. Which system of equations could be used? 

• x + y = 1550
  y  = 4x
• x + y = 1550
  y = x + 4
• y - x = 1550
  y = 4x
• y = 1550 + x
  y = x + 4

Tags

CCSS.8.EE.C.8C

Solve for x and y
3x + 2y = 16
7x + y = 19

• (-2,5)
• (-2,-5)
• (2,-5)
• (2,5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6