Really none of the above.
A principal square root of a real number is a positive real number (or a positive real number times i, if you're up to complex numbers, but let's assume not.) It's not necessarily a positive integer, √2 being the obvious example.
Is √2 a positive fraction? We can write it as √2 / 1 so I suppose it is. It's certainly not a rational number. Even if we grant irrationals as fractions surely √0=0 isn't a positive fraction. So "always" isn't correct.
I'd go with none of the above, but if I had to choose I'd choose D.
Answer:
Its 3
Step-by-step explanation:
Answer:
We are to find the error made by Sadie and then find the correct simplification.
The error Sadie made is that she wrote 
as 
instead of 
.
The square root of 
is 
and so she could have further simplified.
The correct simplification is shown below:
From the given question we come to know of certain number of facts and they are:
At 1:00 PM the water level of the pond was = 13 inches
At 1:30 PM the water level of the pond was = 18 inches
At 2:30 PM the water level of the pond was = 28 inches
From the above given facts we can easily find the amount of water changing every half an hour.
Amount of increase in water from 1:00PM to 1:30 PM = (18 - 13) inches
= 5 inches
Amount of increase in water level from 1:30PM to 2:30PM = (28 -18) inches
= 10 inches
From the above two deductions we can come to the conclusion the the constant rate of change in water level is 5 inches for every half an hour.
