Finding the range

[Shogun]

In a triangle CDE, CD =3y, DE=30, and CE=45. Determine the range of possible values for y.

45-30=15 3y=CD=75
3y=CD=3
3y = 15
3y = 3

y =5 y =25


Did I do this correctly? How do I write my answer correctly?

 

[skeeter]

the sum of any two sides of a triangle must be greater than the 3rd side ...

30 + 45 > 3y
3y + 45 > 30
3y + 30 > 45

solving each inequality for y ...

y < 25
y > -5
y > 5

now, using the most restrictive conditions yields 5 < y < 25

 

[Shogun]

Thankyou for your help