Solving Systems of Equations

To eliminate a variable in the system, should you add the equations or subtract the equations?

• Add

• Subtract

• Neither

What would be the first step in finding the solution using elimination?

• you cannot solve this using elimination

• cross out the 2x and 3x

• Add the like terms. The y terms will zero out.

• change to slope intercept form and graph

Amy sold 10 packages of sugar cookies and 2 packages of oatmeal cookies for $56. Adam sold 9 packages of sugar cookies and 3 packages of oatmeal cookies for $60. What is the price of 1 pack of sugar cookies and 1 pack of oatmeal cookies?

• Sugar Cookies $5 
  Oatmeal Cookies $3

• Sugar Cookies $4
  Oatmeal Cookies $8

• Sugar Cookies $2
  Oatmeal Cookies $6

• Sugar Cookies $3
  Oatmeal Cookies $6

Your family goes to a restaurant for dinner. There are 6 people in your family. Some order the chicken dinner for $14.80 and some order steak for $17. If the total bill was $91, how many of each kind of dinner was purchased?

• 3 chicken, 3 steak

• 5 chicken, 1 steak

• 1 chicken, 5 steak

• 4 chicken, 2 steak

Solve the following system of equations. What is the point of intersection of the two lines?

y = 2x - 2 and y = 4

• (-3, 4)

• (3, 4)

• (4, 3)

• (4, -3)

Solve the following system of equations. What is the point of intersection of the two lines?

y = 2x and y = -x + 6

• (2, 4)

• (6, 12)

• (3, 6)

• (-2, 4)

Solve the following system of

equations. What is the point of intersection of the two lines?

y = x + 9 and 4x + 7y = 19

• (-4, 5)

• (4, 13)

• (4, -5)

• (5, -4)

Solve the system by substitution.
 
5x + 4y= −14
y =  −7x  −  15 

• (-2, -1)

• (1, -2)

• (-2, 1)

• (-1, -2)

How many solutions does the graph have?

• One solution

• No solution

• Infinite solutions

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