Model Linear Systems

Choose the two equations you would use to solve the problem shown: The sum of two numbers is 21. The difference is 9. What are the numbers?

Which two equations could you use to find the answer to the problem shown?:

At Elisa's Printing Company LLC there are two kinds of printing presses: Model A which can print 70 books per day and Model B which can print 55 books per day. The company owns 14 total printing presses and this allows them to print 905 books per day. How many of each type of press do they have?

Which of the following are the two equations you could use to solve this problem? You purchase 8 gallons of paint and 3 brushes for $152.50. The next day, you purchase 6 gallons of paint and 2 brushes for $113. How much does each gallon of paint and each brush cost?

You purchase 8 gallons of paint and 3 brushes for $152.50. The next day, you purchase 6 gallons of paint and 2 brushes for $113.

How much does one gallon of paint cost?

• $17.00

• $13.50

• $5.50

• $34

What is the solution to the following system of equations?

• (-1,-1)

• (1,1)

• (1,-1)

• (-1,1)

Select the correct equation.

Choose the two equations that can be used to solve the problem shown: The sum of twice a number and 4 times another number is 4. The difference of the numbers is 5. Find the numbers.

Choose the two numbers that fit the statements below: The sum of twice a number and 4 times another number is 4. The difference of the numbers is 5. Find the numbers.

• 4

• -4

• 1

• -1

• Any point on one of the dashed lines is a solution to the system of inequalities.

• The point where the dashed lines intersect is the solution to the system of inequalities.

• Any point that is in the shaded region for at least one inequality is a solution to the system of inequalities.

• Any point in the region where the shadings overlap is a solution to the system of inequalities.

You have started to think about saving money to purchase a car. You know you can earn money by doing yard work or by babysitting your neighbor’s kids. You earn $8 per hour doing yard work and $6 per hour babysitting. You want to earn at least $96 this week. With all of your homework, you know you don’t want to work more than 20 hours in a week. Let x = # hours doing yard work and let y = # of hours babysitting.  When you graph the lines for the inequalities you could write for this scenario, what will the lines look like?

• Both lines are dashed.

• Both lines are solid.

• One line is dashed and the other is solid.