Answer:
D
Step-by-step explanation:
We can safely assume we are dealing with an arithmetic scale because the type of scale isn't mentioned anywhere. The more right a point is on the scale, the higher its value is. We are given two points of the scale: 3 and 4. Because the scale is arithmetic, we know that 3.8 must lie on 4/5s of the length between 3 and 4 to the right of 3, which is exactly where point D is.
The equation is 
<u>Explanation:</u>
We have to first find the mid-point of the segment, the formula for which is

So, the midpoint will be 
= 
It is the point at which the segment will be bisected.
Since we are finding a perpendicular bisector, we must determine what slope is perpendicular to that of the existing segment. To determine the segment's slope, we use the slope formula 
The slope is
= 
Perpendicular lines have opposite and reciprocal slopes. The opposite reciprocal of
is 
To write an equation, substitute the values in y = mx + c
WHere,
y = -1
x = 3
m = 3/2
Solving for c:

Thus, the equation becomes:

Okay so lets call Leah "L" and her cousin "C". We know that L+C=36 ... we also know that Leah is twice her cousins age. Therefore, L=2 times C, or L=2C. This is because Leah's age is equivalent to twice as much as her cousin's.
Now that you know that L=2C, you can plug this back into the equation. This should make it so that's there's only one variable now!
L+C=36
(2C)+C=36 ... here we subbed in L=2C
3C=36 ... we add up the C's
C=12 ... we isolate for C by dividing both sides by 3
So her cousin's age is 12 years old. Leah's age is twice that. Thus, she's 24. If you add the two up: 12+24, you indeed get 36. Hope that helps :))
Answer: 3/5
Step-by-step explanation: simplified completely
The best definition for the term substitution would be...
the action of replacing someone or something with another person or thing.