Formative Assessment 32

Assessment Problem: 

Can x=3 be a solution to a system of inequalities?

Common Responses: 

Yes, because the solution to 5x-10>0 is x>2 and x=3 satisfies this; it is a solution, but not the ONLY solution.
There are systems in which the ONLY solution is x =3:
3x – 9 > 0 and 2x – 6 < 0.

Mathematical Issues: 

Students convolute inequalities and equations. It can cause trouble to think and equation is a solution to a system of inequalities. They fail to consider ALL solutions rather than just a solution.

Domain: 
Algebraic Relations
Theme: 
Inequalities
Common Core Standards: 
6.EE Expressions and Equations
Research References: 
Reference (Tsamir & Bazzini, 2001)