Solving Systems of Equations by Substitution

3x + 2y = 16
7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

3x + y = 1
y = 4x + 1

• (0, -1)

• No Solution

• (0, 8)

• (0, 1)

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

3x + 2y = 8
-x + y = -11

• (-5,6)

• (6,-11)

• (-6,-5)

• (6,-5)

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

• intersecting lines

• parallel lines

• skew lines

• intersecting lines

How many solutions?

• One Solution

• No solution

• Infinitely Many Solutions

Solve:
y = -1x - 5
4x - 8y = 4

• (-3, -2)

• (5, -7)

• (3, 9)

• (-5, 4)

3x + 2y = 8

-x + y = -11

• (-5,6)

• (6,-11)

• (-6,-5)

• (6,-5)

Solve:

x = -3y - 17

2x + 3y = -7

• (1, -20)

• (10, 0)

• (-5, -2)

• (10 , -9)

What is the solution to the system of equations?

• (3,1)

• (1,3)

• (3,-1)

• (3,-1)