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)