Systems of Equations Strategy

What is the solution to this system of equations? Solve by substitution or graphing. (Hint: use your graphing calculator!!!)

• (7, -8)

• (-7, 8)

• (-7, -8)

• (7, 8)

Which is the best method for solving this system of equations?

-4x-2y=-12

4x+8y=-24

• Substitution

• Elimination

• Equal Values

Which is the best method for solving this system of equations?

y = -2x + 3

8x + 4y = 12

• Substitution

• Graphing

• Elimination

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

Which is the best method for solving this system of equations?

• Elimination

• Substitution

• Graphing, Not Graphing...

  (aka Picturing the Graph)

  (aka Using graphing skills but not actually graphing)

When using any of the 3 methods to solve a system of linear equations the resulting solution is the same no matter which method is used.

• True; using any method will result in the correct solution.

• False; the solution varies because the solution depends on which method is used.

Solve the system by elimination. 
−4x − 4y = 0
4x + 4y = 0 

• (−6, −4) 

• Infinite number of solutions  

• (−6, 10) 

• (6, 4) 

What variable do you eliminate?

4x + 8y = 20

−4x + 2y = −30

• X because they have opposite signs

• Y because they have opposite signs

If a system of equations has no solution, what does the graph look like? 

• intersecting lines

• parallel lines

• skew lines

• intersecting lines

What is the solution?

• (1, -1)

• (-1, 1)

• (0, -2)

• (2, 0)