Answer:
The arc length is 
Step-by-step explanation:
Given that,
The given curve between the specified points is

The points from
to 
We need to calculate the value of 
Using given equation

On differentiating w.r.to y




We need to calculate the arc length
Using formula of arc length

Put the value into the formula








Put the limits


Hence, The arc length is 
Answer:
The missing reason is Subtraction Property of Equality.
Step-by-step explanation:
⇒ (Given)
On Solving we get;
Multiplying 2 on both side we get;

⇒ (Multiplication Property of Equality)
Now Subtracting Both side by 10 we get;

⇒ (Subtraction Property of Equality)
Now Dividing both side by 3 we get;

⇒ (Division Property of Equality)
Hence the missing reason is Subtraction Property of Equality.
The answer is the second one