I need immediate help!! please! Solve for x under assumption that x0. x-45/x

Question

I need immediate help!! please!
Solve for x under assumption that x>0.
x-45/x<-4. (answer in interval notation)

anonymous · Answer

@satellite73  can you help me?

ash2326 · Answer

$$x-\frac{45}{x} <-4$$
Is this right?

anonymous · Answer

yeah that's what it is

ash2326 · Answer

Now we know x>0
So we can multiply the whole equation by x, 
$$x^2-45x<-4x$$
Do you get this step?

anonymous · Answer

yeah I get that, the part where I get stuck is just to know which are the values

ash2326 · Answer

Could you simplify this, bring all the terms to one side?

anonymous · Answer

I know up to (x+9)(x-5)<0

anonymous · Answer

yes I can it would be
x^2+4x-45<0

ash2326 · Answer

Good, now find the range :)

anonymous · Answer

do you know the answer? is it (0,5)?

ash2326 · Answer

From this you would get a range of
(-9, 5)
Is that right?

anonymous · Answer

see I go up to -9<x<5

anonymous · Answer

yeah, but since it says under assumption that x>0, I get confused

ash2326 · Answer

yeah, but we know already that x is positive, so it should be 0<x<5
Do you get this?

ash2326 · Answer

that means that we are given x>0, we start from that

ash2326 · Answer

Open Study is having problem right now, 
We can safely assume that x>0 and then we can proceed with the problem.

anonymous · Answer

Yeah, this thing got slow and what not. But okay, that's what I thought I just wasn't sure. Thank you ash (: