X+y+z=t
simple..
there are no other numbers that we have to follow like (1/2x or 3/4y) so it is just all together=t. the x, y, z will equal t because t is the total number of students taking three languages. And that number should be equivalent to x,y,z combined.
otherwise?? i d k<span />
Answer:
AC = 30
Step-by-step explanation:
Start with:

Combine like terms.

Subtract
from both sides of the equation.

Subtract
from both sides of the equation.

Then, substitute
for
in 

Multiply.

Finally, add.

Answer:
100.26
Step-by-step explanation:
You would find the area of the semi circles on either side of the rectangle by plugging the diameter into the formula for the area of a circle. Then you would add that to the are of the rectangle.
This is what that would look like:
1. Divide 6 (the diameter) by 2 because 


2. plug into the formula 

3. square the 3

4. multiply 9 by 3.14 (pi)

This means the area of both the semi circles added together would equal 28.26
Then you would use the formula
to find the area of the rectangle
1. plug in the numbers given
· 
2. solve

Then add the area of the semicircles to the area of the rectangle

to get the area of the entire figure:

A. 12; Least common denominator is the least multiple that the denominator have together. So you multiply the denominators until you get the first number they both have in common.
6*1 = 6
6*2 =12
4*1 =4
4*2 =8
4*3 = 12
Since the first number they both have in common is 12, the least common denominator is 12
Answer: 10
Imagine you have 2 slots or boxes that are empty. They represent the possible choices for the letter you pick. For example, you can place B in slot 1 and D in slot 2. There are 5 choices for slot 1 (A,B,C,D,E) and four choices for slot 2. Why 4? Because after we pick the letter for slot 1, we have one less letter to pick from. We can't reuse that letter.
Now multiply those values 5 and 4 to get 20. There are 20 different ways to pick a pair of letters from a pool of 5 total. However, order does NOT matter because the segment AB is the same as BA. Since order doesn't matter, we are doubly counting when we shouldn't. In other words, our count is two times higher than it should be. Instead of 20 pairs, it's actually 20/2 = 10 pairs. That's why the answer is 10.
The list of 10 segments are: {AB,AC,AD,AE,BC,BD,BE,CD,CE,DE}
Side note: you can use the nCr combination formula with n = 5 and r = 2 to get the same answer.