Answer:
-2b/(a-b)
Step-by-step explanation:
1− (a+b/a−b)
We need to get a common denominator of a-b
1 = (a-b)/(a-b)
Replace 1 with (a-b)/(a-b)
(a-b)/(a-b) - (a+b)/(a-b)
Put over the common denominator
(a-b) - (a+b)
-----------------
(a-b)
Distribute the minus sign.
(a-b) - a-b)
-----------------
(a-b)
a-a-b-b
---------------
a-b
-2b
----------
a-b
The answer is: 
The explanation is shown below:
1- You have the following expression given in the exercise:

2- When you multiply signs, you obtain:

3. Now, you must add like terms, as following:

4. Therefore, you have that the expression simplified is:

Answer:
9.21954445729
Step-by-step explanation:
use distance formula
Answer:
R2->R3
Step-by-step explanation: