If we let x be the speed of the boat you are taking to the island (the steamboat), then we know that the speed of the other boat (the tall ship) is 10 knots less than the steamboat's. So the speed of the tall ship (for the return trip) is (x - 10) knots.
Recall that for 3 vectors
, all in
, the vector triple product

So

Also recall the scalar triple product,

which gives the signed volume of the parallelipiped generated by the three vectors
. When either
or
, the parallelipepid is degenerate and has 0 volume, so

and the above reduces to

so that
![(u\times v)\cdot[(v\times w)\times(w\times u)]=(u\times v)\cdot((v\times w)\cdot u)w](https://tex.z-dn.net/?f=%28u%5Ctimes%20v%29%5Ccdot%5B%28v%5Ctimes%20w%29%5Ctimes%28w%5Ctimes%20u%29%5D%3D%28u%5Ctimes%20v%29%5Ccdot%28%28v%5Ctimes%20w%29%5Ccdot%20u%29w)
The scalar triple product has the following property:

Since
is a scalar, we can factor it out to get

and by the property above we have

and so we end up with
![[u\cdot(v\times w)]^2](https://tex.z-dn.net/?f=%5Bu%5Ccdot%28v%5Ctimes%20w%29%5D%5E2)
as required.
Answer:
3
Step-by-step explanation:
Note that
(
)² = a, for example
(
)² = 10² = 100 ← value inside the radical
Thus
(
)² = 3
Answer: 1+$11=$12
$12 +$51= $75 tickets that Henry bought
Answer:
126 all you have to do is take the two measurements and add them together