Solving Two-Step Equation Find the Error

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

Using the "opposite operation" to "undo" and isolate the variable when solving an equation is more commonly called...

• Inverse operations

• math

• variable

• PEMDAS

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

Find the Error
What error did the student make when solving the equation:
5x + 6 =  66
5x - 6 = 66 -6
5x = 60
5*5x= 60*5
x = 300

• The student subtracted 6 from both sides instead of adding

• Student multiplied by 5 instead of dividing by 5

• Student got the wrong answer when subtracting 66-6

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

5x - 4 + 2x = 3

• 1

• 2

• 3

• 4

The goal of solving a one, two, or multi-step equations is to:

• Find the constant

• Find the coefficient

• Find the value of the variable

• Guess and check

What is the first step to solve this equation:
11 - 3x = 44

• Add 3 to both sides

• Subtract 11 from both sides

• Add 11 to both sides

• Divide 3 on both sides.

What operation would you perform first and then second when solving for m in the following equation? 10 + 7m = 17

• subtract 10, divide by 7

• divide by 7, subtract 10

• multiply by 7, add 10

• add 10, multiply by 7

Find the error in the problem.

• Should have added 19 to -1.

• Should have subtracted 3k instead of adding 3k to both sides.

• Should have gotten k = 20 since two negatives make a positve.

• There is no error.

What is the next step to solve this equation?
3x + 6 = 10 + 7x

• Add 6 to both sides of the equation

• Add 10 to both sides of the equation

• Add 7x to both sides of the equation

• Subtract 7x from both sides of the equation