When
, we have


and of course 3 | 6. ("3 divides 6", in case the notation is unfamiliar.)
Suppose this is true for
, that

Now for
, we have

so we know the left side is at least divisible by
by our assumption.
It remains to show that

which is easily done with Fermat's little theorem. It says

where
is prime and
is any integer. Then for any positive integer
,

Furthermore,

which goes all the way down to

So, we find that

QED
Answer:
I think it's A
Step-by-step explanation:
Given:
Consider the completer question is "If ∆BTS≅∆GHD, BS=25, TS=14, BT=31, GD=4x-11, m∠S=56, m∠B=21 and m∠H=(7y+5), find the values of x and y.
To find:
The values of x and y.
Solution:
We have,
(Given)
(CPCTC)



Divide both sides by 4.

In ∆BTS,
(Angle sum property)




Now,
(CPCTC)



Divide both sides by 7.

Therefore, the value of x is 9 and value of y is 14.
Answer:
76.3 degrees
Step-by-step explanation:
We use inverse cosine to find the angle.
arccos(1.9/8) = 76.26 deg