I believe #7 would be 5:13, #8 to be 6:7, #9 to be 13:18, #10 to be 18:5.
I hope this helps.
Answer:
D
Step-by-step explanation:
First, let us figure out what is graphed and then manipulate each answer to try to match it.
The one with a positive slope is

The one with the negative slope is

Now that we have our graphed system of inequalities, we can try to match them to an answer.
A. while the x-2 is the same, the other does not have an x, so it cannot match.
B. The second inequality has the wrong sign, so it is impossible for this to be our answer.
C. When each of these are solved for y, you get
. Neither of these match so this cannot be correct.
D. When the first inequality is solved you get 
When the second inequality is solved you get 
As both of these answers match our graphed inequalities, D is the correct answer.
Search up heating curve chemistry: it should look somewhat like that lol :). But, the last interval should have a small slope, the middle interval a big slope, and the first interval: a medium slope.
Answer:
The answer is -7.15, hope this helps.
What do we know about those two lines?
They are perpendicular, meaning they have the same slope.
We know the slope of both is not zero (neither is vertical).
Therefore either
1) Both slopes are positive and therefore the product is positive
2) Both slopes are negative and therefore the product is positive (minus by a minus is a plus)
For the y intercepts, we know that the line P passes through the origin.
Therefore its Y intercept is zero.
[draw it if this is not obvious and ask where does it cross the y axis]
Therefore the Y intercept of line K and line P is zero.
[anything multiplied by a zero is a zero]
So we know that the product of slopes is positive, and we know that the product of Y intercepts is zero.
So the product of slopes must be greater.
Answer A