Step Equations Find Mistakes

Solve the equation:
3(x - 1) = 2x + 9

• x = 12
• no solution
• x = 10
• x = 6

Solve:
3(3x - 6) = 18

• x = 4
• x = -4
• no solution
• infinite solutions

Tags

CCSS.7.EE.B.4A

8v - 4(v + 8) = 8

• 2
• 10
• 4
• -4 

Tags

CCSS.8.EE.C.7B

2x - 3 + 4x = 27

• 12
• 4
• 5
• 15

Tags

CCSS.8.EE.C.7B

4x + 10 = -26

• 4
• -4
• -9
• 9

Tags

CCSS.7.EE.B.4A

What is the first step in solving the equation 2a - 4(a - 5) = 10

• Add 4 to both sides
• Add the 2a and a 
• Distribute 4 to a and -5
• Distribute -4 to a and -5

Tags

CCSS.8.EE.C.7B

What is the first step in solving this equation? 
5x + 7 = 12

• Divide by 5
• Subtract 5
• Multiply by 7
• Subtract 7

Tags

CCSS.7.EE.B.4A

12+5w-4w=15

• w=1
• w=3
• w=5
• w=4

Tags

CCSS.8.EE.C.7B

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