Option C:
The coefficient of 
is 40.
Solution:
Given expression:
Using binomial theorem:
Here 
Substitute in the binomial formula, we get
Now to expand the summation, substitute i = 0, 1, 2, 3, 4 and 5.
Let us solve the term one by one.
Substitute these into the above expansion.
The coefficient of is 40.
Option C is the correct answer.
Alright, so for AB and CD to be parallel, CX and DX would have to be equal, as is with AX and BX. In addition, for CD and AB to be parallel, all sides in both triangles are either equal or not all sides in even one triangle are equal. Therefore, CD is not 3. In addition, two sides of a triangle combined must be greater than the third, so that leaves 5, 4, and 2 for CD. If it was 5, that would mean that all sides are equal, so that leaves 4 and 2. However, I don't see anything to prove either one right, sorry:/
If you’re asking for the cost of the drink, the drink would be $1. This is because 2 sandwiches would cost $10 and that means 1 sandwich would make it $5. If 2 sandwiches cost $10, the remaining $2 in the $12 dollars would be the drinks. 2 drinks for $2 would make 1 drink for $1. So the cost of 5 drinks is $5 or $1 per drink.
If confused, don’t be shy to ask :)
