posted by JCEE .
If the cost of a cell phone has decreased 400% during the past 10 years, does that correspond to a cost decrease of four times? Explain your answer as though you were talking to someone who has never taken algebra.
I guess you have to explain what a cost decrease of four times means to you, since that is not a common math term.
What is a cost decrease of one time?
What is a cost decrease of two times?
It is total nonsense, and I am very surprised a "math" teacher is "teaching" such nonsense.
Now on the second point of nonsense. Is the phone free? A 100% decrease would make the phone zero cost. If it decreased more than that you should get paid to take a telephone.
You are at the wrong school. I hope you are not paying for this education.