all the books say |x|>a is written as x>a or X<-a

[nicknation]

all the books say |x|>a is written as x>a or X<-a
why cant i rite it like -a>X>A?

[stapel_eliz]

Try plugging a value in for "a", and taking the "x" out of the middle. For instance, given |x| > 3, the books say:

. . . . .x < -3 or x > 3

Your form says:

. . . . .-3 > x > 3

...which, by making the above-mentioned change, is:

. . . . .-3 > 3

But is any negative number greater than any positive number?

So formatting your way leads to nonsensical statements. That's why you shouldn't do that. (Plus, your teacher will probably count off, maybe a lot....)