The value of the expression decreases
There are 40 cats in the ecosystem.
You set 1/5 equal to x/200. Then you cross multiply the fractions to get 5x=200. You divide both terms by 5 to get x, which equals 40.
Answer:
Internal validity
Step-by-step explanation:
The internal validity here is weak
Internal validity describes the extent to which an evidence weighs the cause and effect claim. In this study, the internal validity that brought about failure in the new exam is mainly due to the environment where the exam was written and not the new exam itself.
So this validity is weak in claiming that the new exam is not a good substitute for the old exam.
Putting them in the same good environment might help the researchers to draw a better conclusion.
This isn't really a geometry problem. It's just an addition of fractions.
You know that 'perimeter' means 'the distance all the way around'.
And you know the length of all the sides of the parallelogram.
All you need to do is add them up !
(13/12) + (3/13) + (13/12) + (3/13) = the perimeter
Notice that two of the sides are equal, and the other two sides are also equal.
So you can make the job a little easier if you add up the twelfths first
(13/12) + (13/12) = 26/12
and then add up the thirteenths ...
(3/13) + (3/13) = 6/13 .
Now, the perimeter looks a little bit less complicated.
It's just
(26/12) + (6/13) = the perimeter.
This is the tough part. Before you can add fractions, they need to have
a common denominator.
The smallest common denominator for 12ths and 13ths is <em>156 </em>!
Change each fraction to (<em>something over 156</em>), and add um up.
I'll leave that part to you.
