Review Graphing and Substitution Methods

Solve the system by substitution.

−x + 5y = 12

y = −2x − 2

• (−2, −7)

• (−2, 2)

• (−2, −2)

• (2, −2)

How many solutions?

• One Solution

• No solution

• Infinitely Many Solutions

Identify which method for solving systems is being described by this fact: The intersection point of the two lines is an ordered pair (x, y) and determines the value of the solution to the system of equations.

• Graphing

• Substitution

• Elimination

Identify which method for solving systems is being described by this fact:

If one equation is isolated like y = 2x or

x = 7 - 4y then this method should be used.

• Graphing

• Substitution

• Elimination

If the solution to a system of equations is the point (3, 5.25), which method of solving the system would be the WORST choice?

• Graphing

• Substitution

• Elimination

• All Methods Would Be Good Choices

Which variable would be the EASIEST to isolate for the substitution method in the system?

• X in the first equation

• Y in the first equation

• X in the second equation

• Y in the second equation

Which variable would be the BEST choice to isolate for the substitution method in the system?

• X in the first equation

• Y in the first equation

• X in the second equation

• Y in the second equation

• Substitution

• Elimination

Solve for x and y
y = 2x + 1
y = 4x - 1

• (1,3)

• (-1,-3)

• (-1,3)

• (3,1)

What is the solution?

• (1, -1)

• (-1, 1)

• (0, -2)

• (2, 0)