Since you have provided me with • symbol I must assume it's about function multiplication, but since standard keyboard doesn't have the function composition symbol
I must assume you meant either.
1. Case you meant multiplication.

2. Case you meant composition.

Hope this helps. Next time please use LaTeX to format your equations so that others can give you answers as well.
18 ft. just took this test
2.54 cm in customary = 1 inch
Answer:

Step-by-step explanation:
Let be "x" the lenght of the longest side, "y" the lenght of the middle side and "z" the lenght of the shortest side.
The perimeter is:
[Equation 1]
We know that the longest side is 10 less than twice the middle side length. This can be expressed as:
[Equation 2]
And the middle side length is three less than three times the shortest side length. This is:
[Equation 3]
The steps are:
- Solve for "z" from the third equation:

[Equation 4]
- Substitute [Equation 4] into [Equation 1]
- Substitute [Equation 2] into [Equation 1]
Then:

- Solve for "y":

- Substitute this value into [Equation 2] and into [Equation 4]:
