Solving Systems of Equations Error Analysis

Problem #22

ERROR ANALYSIS: Correct the error in solving the system of linear equations.

• (-3, 4)

• (-3, -4)

• (4, -3)

• (3, -4)

Describe the error in solving the system of linear equations.

• The y-term was multiplied by -5 instead of 5.

• The y-term was multiplied by 5 instead of -5.

Use a method from Activity 1 to solve the system.

• (6, 2)

• (2, 1)

• (-1, 3)

• (1, -3)

Problem a

RAFFLE TICKETS: You and your friend are selling raffle tickets for a new laptop. You sell 14 more tickets than your friend sells. Together, you and your friend sell 58 tickets.

a. Write a system of linear equations that represents this situation. (Select all that apply.)

Problem b, your friend

RAFFLE TICKETS: You and your friend are selling raffle tickets for a new laptop. You sell 14 more tickets than your friend sells. Together, you and your friend sell 58 tickets.

b. How many tickets do each of you sell?

your friend sells ___ tickets

Mathematical Equivalence

ON

Problem #14

ERROR ANALYSIS: Correct the error in solving the system of linear equations.

• one solution

• no solution

• infinitely many solutions

Problem #14

ERROR ANALYSIS: Describe the error in solving the system of linear equations.

• The lines have different y-intercepts, so the lines are parallel.

• The lines have different slopes.

• The lines have the same slope and the same y-intercept.

REASONING: One equation in a system of linear equations has a slope of − 3. The other equation has a slope of 4. How many solutions does the system have?

• one solution

• no solution

• infinitely many solutions

REASONING: One equation in a system of linear equations has a slope of − 3. The other equation has a slope of 4. How many solutions does the system have? Explain.

• The lines have different y-intercepts, so the lines are parallel.

• The lines have different slopes, they will intersect in one point.

MONEY:

You and a friend both work two different jobs. The system of linear equations represents the total earnings for x hours worked at the first job and y hours worked at the second job. Your friend earns twice as much as you.

One week, both of you work 4 hours at the first job. How many hours do you and your friend work at the second job?

_____ hours

Mathematical Equivalence

ON