Error Analysis in Solving Equations

What is the error?

• Adding 1 to both sides

• Distributing the negative sign when multiplying –3(x + 2)

• Subtracting 6 from both sides

• x should equal 5/3

How many solutions are there?

• one solution

• no solution

• infinite solutions

• none of these

"I know that No Solution is correct because when solved the left side of the equation is ___________ the right side of the equation."

• the same as

• a number different than

• a variable equal to a constant on

"I know that Infinite Solution is correct because when solved the left side of the equation is ___________ the right side of the equation."

• the same as

• a number different than

• a variable equal to a constant on

What error(s) did this student make?

• Did not combine like terms

• Needed to add 2x instead of subtract

• Should not use inverse operations on the same side of the equal sign

• No errors; the student is correct

This student made an error with the disruptive property. What did s/he do wrong?

• You can't drop down a -16; You need to keep it positive

• You should only multiply the -2 & 8m; the 8 should stay the same

• You need to multiply -2 to both parts inside the parenthesis; -2*8m is -16m and -2*8 is -16

• You should divide -2 from both sides first

This student subtracted 2 from both sides of the equation. What should s/he have done?

• Nothing; This is correct

• S/He should have added a -2 to both sides

• S/He should have added 2 to both sides

• Subtracted 2x instead of 2

What type of mistake did this student make?

• The student did not use the correct inverse operations

• The student did not add/subtract negative numbers correctly

• There are no mistakes

Which of the following correctly identifies the mistake this student made?

• There are no mistakes

• 
• 
• 

This student's mistake is circled in yellow. What should s/he put here.