Solving Equations Errors and Steps

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

Tags

CCSS.HSA.REI.A.1

CCSS.HSA.REI.B.3

How many solutions does the equation below have?
5 + 2(n + 1) = 2n

• Identity
• One Solution
• No Solution
• Two Solutions

Tags

CCSS.8.EE.C.7A

How many solutions does the equation below have?
5h - 7 = 5(h - 2) + 3

• Identity
• No solution
• Three Solutions
• One Solution

Tags

CCSS.8.EE.C.7A

How many solutions does the equation below have?
6(3a +1) - 30 = 3(2a - 4)

• Identity
• No Solution
• Three Solutions
• One Solution

Tags

CCSS.8.EE.C.7A

How many solutions does the equation below have?
6(3a +1) - 30 = 3(2a - 4)

• Identity
• No Solution
• Three Solutions
• One Solution

Tags

CCSS.8.EE.C.7A

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

• Yes
• No

Tags

CCSS.HSA.REI.A.1

Is the solution below correct?
-6z + 13 = 7z
+6z           +6z
13 = 13z
z = 1

• Yes
• No

Tags

CCSS.HSA.REI.A.1

What is the first step to solve this equation?
x - 5 = 7 - 2x

• Add 7 to both sides of the equation

• Add 2x to both sides of the equation

• Subtract 2x from both sides of the equation

• Subtract 5 from both sides of the equation

Tags

CCSS.8.EE.C.7

What is the next step to solve this equation?
3x - 5 = 7

• Add 5 to both sides of the equation

• Add 3x to both sides of the equation

• Subtract 5 from both sides of the equation

• Subtract 7 from both sides of the equation

Tags

CCSS.7.EE.B.4A