Solving systems using substitution and elimination

-3x - 8y = 20

-5x + y = 19

-7x - 2y = -13

x - 2y = 11

9x-3y=-3

-5x+3y=-1

Which variable will be eliminated?

• the x

• the y

Solve using elimination.

x+y=3

-x-10y=-30

• (0,3)

• (0,-3)

• no solution

• infinitely many solution

Solve the system of equations.

• (3, 33)

• (7, 77)

• (2, 22)

• No solution

• Infinite solutions

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 (linear combination)

10x-8y=-30

-10x+9y=25

Which variable will be eliminated?

• the x

• the y

What is the solution?

• (1, -1)
• (-1, 1)
• (0, -2)
• (2, 0)

Determine how many solutions the system has.

• One Solution
• No Solutions
• Infinitely Many Solutions
• Mikey is my friend.

Solve the system of equations.

• (3, -24)

• (0, 4)

• (-24, 3)

• No solution

• Infinite solutions