# hey got a question here

posted by
**David Lee** on
.

hey if dy/dx= -2 why is it wrong to say that y is alwats decreasing at a rate of -2? I don't really get it.

It is better to say that y is always decreasing with a slope of -2 on a graph of y(x), or at a rate of -2 per change in x. Saying that a rate is a number does not say enough about what variables are involved.