(a-b) X (a+b)
= aXa - bXa +aXb -bXb (distributing)
Now, cross product of a vector with itself = 0
so, aXa = 0, bXb = 0
Also, aXb = - bXa
so,
(a-b) X (a+b) = 0 + aXb + aXb + 0
= 2aXb
hence, proved :)
Answer:
14
Step-by-step explanation:
We are given with two
numbers whose first
are same.
It is given that their sum is 
adding the last two corresponding digits gives,

Now adding the rest,
to get 
should not give anything to carry as that will make A in decimal to satisfy the addition.
Therefore,

Thus 
And finally,

Thus 
Now simplifying

Thus
is the answer.
Answer:
87.92in³
Step-by-step explanation:
Volume of cylinder formula:

Plug in the values using 3.14 for pi:
V = 3.14(2)^2(7)
V = 87.92in³
1 fin = 8 grams
4 fins = 4 x 8 = 24 grams total
Answer:
15 bulbs are red.
Step-by-step explanation: Because 75 is 3 times as big as 25 so every 1 green light bulb 3 red light bulbs will be deflective.