One Step Equations Error Analysis

Find the error in the problem below
19 - 2k = 3k - 1
     +3k   +3k
19 + 1k = -1
-19           -19
k = -20

• They should have divided by 1 for the last step

• They should add 19 instead of subtracting 19

• I can not find an error

• Instead of adding 3k they should subtract 3k

Tags

CCSS.HSA.REI.A.1

Find the Error
What error did the student make when solving the equation:
1/5x + 6 = 3/5x + 5
1x + 6 = 3x + 5
-2x + 6 = 5
-2x = -1
x = 1/2

• The student found an incorrect common denominator

• The student did not multiply all terms by the common denominator

• The student did not use opposite operations appropriately

• The student did not correctly eliminate the variable from one side of the equation

Is the solution below correct?
5d = 2d - 18
-2d   -2d
3d = -18
d = 6

• Yes

• No

Tags

CCSS.8.EE.C.7B

4x - 3 = -2x + 4
6x - 3 = 4
6x = 7
x = 7/6

• There is no error

• They should have subtracted 2x

• They should have subtracted 3

• it should be 6/7

Tags

CCSS.HSA.REI.A.1

Mathematical Equivalence

ON

Tags

CCSS.6.EE.B.7

Mathematical Equivalence

ON

Tags

CCSS.6.EE.B.7

Is there a mistake on the equation solved? If so where was the mistake made?

• This equation is solved correctly.

• The mistake was made on the first step of moving the variable to the right side.

• The mistake was made on the second step of moving the constant to the left side.

• The mistake was made on the last step when isolating the variable by removing the coefficient

Tags

CCSS.HSA.REI.A.1

Mathematical Equivalence

ON

Tags

CCSS.6.EE.B.7

Mathematical Equivalence

ON

Tags

CCSS.6.EE.B.7

Solve the equation.

1. Then compare your work.

2. Is there a mistake on the equation solved? If so where was the mistake made? Explain the mistake.

Explain how to solve the problem.