Solving Equations and Simplifying Expressions

Solve the equation: 
x + 7 = 12

• x = 5

• x = 19

• x = -5

• x = 84

In the equation
x + 7 = 12
7 is being added to the variable, x. How should you show your work to isolate the variable and solve the equation? 

• Subtract 7 from both sides. The solution is x = 5.

• Add 7 to both sides.
  The solution is x = 19.

• Multiply both sides by 7 The solution is x = 84.

7(x + 2) + 3 = 73 Step 1: Distribute
7x + 14 + 3 = 73 Step 2: Combine like terms
7x + 17 = 73 Step 3: Subtract 17
                    Step 4: Divide by 7     

• x = -8

• x = 8

• x = - 12.86

• x = 12.86

Simplify the following expression:
-10x + 15 - 3x + 2

• 13x² + 17

• -13x² + 13

• -13x + 17

• -7x + 17

In the expression shown, x, y, and z are values where the expression is defined.

What is the simplest form of the expression? Enter your answer in the space provided.

Mathematical Equivalence

ON

Tags

AI.9.11.B

3(x-6)+2x=22

• x=8

• x=2

• x=18

• x=3

2x - 3 + 4x = 27

• 12

• 4

• 5

• 15

5(x - 3) + 2x = 27

• x = 3

• x = 42/15

• x = 30/7

• x = 6

How do I simplify -18+5p=p+18+18

• Combine like terms

• Move the variable

• Distribute

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