Linear Systems Substitution Graphing

a method of solving a system of equations by taking a variable out and replacing it with an expression.

• Systems by Graphing

• Systems by Substitution

• Systems by Elimination

• Systems by Drawing

Solve the system by substitution.

• (−2, −7)

• (−2, 2)

• (−2, −2)

• (2, −2)

Solve the system by elimination.

7x - y = -10

-7x + 5y = -6

• (-2, -4)

• (-2, -1)

• (-4, -1)

• (6, -8)

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

Solve the system of equations.
y = 4x+1
3x + 2y = 13

• (1, 5)

• (5, 1)

• (0.25, 2)

• ∅

Does the system have one, none or infinite solutions?
8x + 4y = 12
y = -2x + 3

• (0,3)

• (3,0)

• No solution(parallel lines)

• Infinitely many solutions

Solve the system of equations.
x + 2y = -3
x - y = -12

• (-9, 3)

• (-7 ,5)

• (3, 15)

• (9, 6)

• No Solution

• (2, 2)

• (-1, 2)

• (-1, -2)

Homer sells tickets for admission to your school play and collects a total of $104. Admission prices are $6 for adults and $4 for children. He sold 21 tickets total. Write a system to represent this situation assuming "a" represents # of adult tickets and "c" represents # of children's tickets.

• a + c = 21
  6a + 4c = 104

• a + c = 104
  6a + 4c = 21

• a + c = 21
  6c + 4a = 104

• a + c = 104
  6c + 4a = 21

Which image shows a system of linear equations with infinitely many solutions?

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