Solving Equations Find the Mistake

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

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

• Yes

• No

What is the error?

• Adding 2x to 3x

• Subtracting 5 from both sides

• Adding 2x to -2x

• Dividing by 5 on both sides

What is the error?

• Subtracting 1 from both sides

• Dividing by 6 on both sides

• 3(2x+1) equals 6x +1

• x equals 3/4

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

What is the error?

• Adding 5x to each side instead of 5

• Subtracting 7 from both sides

• Dividing -4 by 2 equals 2

• Dividing both sides by 2

What are the best tips to prevent making mistakes when solving equations? Check all that apply

• Copy correctly

• Slow down and think about the next step

• Check your calulations

• Skip it altogether

What is the first error?

• distributing -2

• combining like terms

• subtracting 2

• diving by -4

What is the first error?

• Adding of 12 on both sides

• Dividing by -8

• Distribution of -4

• No error

Where is the first mistake?

• Distribution of the 5

• Distribution of the 10

• subtracting 60x from both sides

• dividing by -50