Equations and systems of equations by substitution

y = -2x + 18
y = 8

• (5, 8)
• (-5, 8)
• (2, 8)
• (-2, 8)

Solve this system of equations. 
y = 2x + 1
y = 4x - 1

• (1,3)
• (-1,-3)
• (-1,3)
• (3,1)

How many solutions?

• One Solution
• No solution
• Infinitely Many Solutions

What is the solution to this system of equations?

• (4, -1)
• (-1, 4)
• (-4, 1)
• (-4, -1)

How many solutions will this system have? 

• No solution
• One Solution
• I Don't Know
• Infinitely Many Solutions

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

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

Which is the best method to use?

y = 6x − 11

−2x − 3y = −7

• Graphing

• Substitution because a variable is isolated.

• Elimination because both equations are in standard form.

Is (1,10) a solution to

y=7x+5

y=x+9

• yes

• no

y = -2x + 5
y = 2x - 11

• No Solution
• (0, 0)
• (3, -1)
• (4, -3)

^{What is the solution?} 

• 1
• -2
• (1, 2)
• (1, -1)