Formative Assessment 50

Assessment Problem: 

1. Solve the equation 2(3x+4) = 6x + 9
2. After solving, could you solve it in another way?
3. What would be the relationship between the graphs of each side of the equation?

Common Responses: 

The correct answer is empty set, meaning that there is no answer. This equation is a false equation (meaning that it leads to a contradiction).
Graphically each side of the equation represents a line and these lines are parallel to each other.  59% of high school student-pairs answered this question correctly. 57% of the participants used symbolic manipulation as their first choice of strategy.

Domain: 
Algebraic Relations
Theme: 
Solving equations
Common Core Standards: 
6.EE Expressions and Equations
Research References: 
(Huntley, Marcus, Kahan, & Miller, 2007)