Question

(If a,b and c are real numbers, for which values of a is each statement true?)
If c<0, then ac 13 years ago

Answer 1

This of this case: if a <0, then ac > 0 because a < 0 and c < 0 (and the product of 2 neg. numbers is positive). so clearly ac > a in this case. So the statement is false.

Answer 2

Oh wait I didn't read the whole question -_-

Answer 3

Ok well still keep what I wrote in mind. Think of another case: If a >0, then ac < 0 because it will be a negative number (a negative number * a positive num. = a negative num.)

So, ac < a is true.

But what happens if a =0?, well then you get 0 < 0 which is false.

So, the condition necessary is that you need a > 0