Take a better pic and i will explain in comment
Given:
The two expressions are


To find:
Whether the given expression are equivalent or non-equivalent.
Solution:
If two expressions are looking different but they are equal after simplification, then they are called equivalent expressions.
The first expression is

The first expression is equal to the second expression after the simplification.
Therefore, the given expressions are equivalent.
Answer:
This other side of the triangle is equal to about 11.7 cm
Step-by-step explanation:
In order to find out the third side of the triangle we will just use the Pythagoras Theorem.

Since we know the hypotenuse and we know one of the legs, in order to find the second leg we just substitute the values and solve the equation and so we get...


And so b ≈ 11.66190