Answer:
(-1,2.5)
Step-by-step explanation:
First of all, let's take a look on the question.

Here, 0 is added to 15 and the resultant is 15 only. So, we can say that 0 when added with any number gives the same number as the resultant.
So, the property is known as <u>Identi</u><u>ty</u> property because 0 is added to get the identity of the same number.
<u>The Correct Option:</u>

So, let's know more...
- Commutative property ➝ a + b = b + a
- Associative property ➝ a + (b + c) = (a + b) + c
- Distributive property ➝ a(b + c) = ab + ac
So this is the general form of these properties which is general observed in the rational numbers.
<u>━━━━━━━━━━━━━━━━━━━━</u>
Let S be the first side.
Longest side is then 2S.
Third side is 2S-10.
Perimeter is sum of all three sides = S+2S+2S-10 = 75
=>
5S-10=75
5S=75+10=85
S=17
Therefore
S=17 is the first side.
Longest side is then 2S=2*17=34.
Third side is 2S-10=2*17-10=24.