Solving Systems of Linear Equations

The solution to a system of equations is any ordered pair that makes both equations true. 

• TRUE
• FALSE

^{What is the solution?} 

• 1
• -2
• (1, 2)
• (1, -1)

Parallel Lines never intersect because...

• they have the same slopes. 
• they have the same y-intercept.
• they have different slopes.
• they have different y-intercepts. 

This system has _____ solutions

• 0
• 1
• 2
• Infinitely many

What is the solution?

• One Solution
• No solution
• Infinitely Many Solutions

You can solve systems using these methods:

• graphing, substitution, and elimination

• rearranging, thinking, and guessing

• only by graphing

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

The solution (x, y) to a system of equations is the point where they...? 

• Run off the graph
• Don't touch
• Intersect
• Exist

What variable do you eliminate?

4x + 8y = 20

−4x + 2y = −30

• X because they have opposite signs

• Y because they have opposite signs

What variable do you eliminate, and what do you multiply the equation(s) by?

5x + y = 9

10x − 7y = −18

• You eliminate x, and multiply the top equation by 11

• You eliminate y, and multiply the top equation by 7