Answer:
198
Step-by-step explanation:
If you take any 3-digit number and change the numbers around and subtract them you will always get 198.
Answer:
6.
Step-by-step explanation:
First you put the numbers in order, 5, 6, 6, 9, 10 then you find the number in the middle, which in this case is 6.
Answer: 
Step-by-step explanation:
Observe in the figure given in the exercise that four right triangles are formed.
In this case you can use the following Trigonometric Identity to solve this exercise:
From the figure you can identify that:

Then, you can substitute values:

The next step is to solve for DE in order to find its value. This is:

Finally, rounding the result to the nearest tenth, you get that this is:

Answer:
D. "If the graph of two variables is not a linear function, then the two variables are not directly proportional"
Step-by-step explanation:
The contrapositive of a statement is basically you changing the conditional part of the statement with its result and then finding the negative of both. This is called Contraposition.
So, for the statement given:
"If two variables are directly proportional, then their graph is a linear function."
The contrapositive will be:
"If the graph of two variables is not a linear function, then the two variables are not directly proportional"
The rule that represents those numbers is .....idk