Answer: 3x²-3y²+8xy
Step-by-step explanation:
When you multiply two factors, you want to use the FOIL method.
First
Outer
Inner
Last
(x+3y)(3x-y) [distribute by FOIL]
3x²-xy+9xy-3y² [combine like terms]
3x²+8xy-3y² [rewrite]
3x²-3y²+8xy
Now, we know the product is 3x²-3y²+8xy.
i think it might be B. :)
Answer:
Step-by-step explanation:
We have been given the equation:
And 
Second equation can be rewritten as:
We will solve the equations:
(1)
(2)
Multiply equation (1) by 5 and equation (2) by 3 we get:
(3)
(4)
Now, subtract (4) from (3) we get:
Now substitute in equation (1) we get:
I believe you are asking in how many ways they can sit. If so:
The 1st can sit anywhere: he has only 1 way to sit
The 2nd can sit in 11 ways, since one seat is already occupied
The 3rd can sit in 10 ways, since 2 seat are already occupied
The 4th can sit in 9 ways, since 3 seat are already occupied
The 5th can sit in 8 ways, since 4 seat are already occupied
--------------------------------------------------------------------------------
The 12th can sit in 1 way, since11 seat are already occupied
General formula for a circular table:
Number of ways they n persons can be seated: (n-1)!
and the 12 can be seated in (12-1)! = 11! = 39,916,800 ways.
This is called circular permutation
The length of each leg of the triangle is 13(sqrt2).
