Help I'm having problems solving this inequality word problem

[Morenita]

The sum of the lengths of any two sides of a triangle must be greater than the length of the third side. What are the possible values of x for this triangle?

(x+5)cm, (3x)cm, and 40cm

This is what I have done so far and I have gotten the wrong answer

x + 5 + 3x > 40 I checked my answer by plugging in what I got for X and I end up with 40>40
4x + 5 > 40 What am I doing wrong?
-5 -5
4x > 35
4 4

X> 8.75

 

[Deleted member 4993]

The sum of the lengths of any two sides of a triangle must be greater than the length of the third side. What are the possible values of x for this triangle?

(x+5)cm, (3x)cm, and 40cm

This is what I have done so far and I have gotten the wrong answer

x + 5 + 3x > 40 I checked my answer by plugging in what I got for X and I end up with 40>40
4x + 5 > 40 What am I doing wrong?
-5 -5
4x > 35
4 4

X> 8.75

Your answer is x > 8.75

That means you can plug in x = 8.76 or x = 8.75001 or x = 8.75000001 but NOT x = 8.75

But you need to check other conditions also. Those being:

(x+5) + 40 > 3x

and

3x + 40 > x + 5

You can see that if make x = 100 (which is greater than 8.75) - it will not make a triangle!