Answer:
P.y =
Step-by-step explanation:
From the given question, since Jesse sends the email to 4 people and the 4 people rebroadcast it to another 4 persons each. And this process continues for a required or given round x, then this is an example of an exponential function.
Thus, the number of emails sent for a given round can be expressed as;
y =
Therefore, the appropriate answer is y = .
So that for four rounds (x = 4), the number of emails sent can be determined as;
y =
=
y = 256
Answer:
It is divisible by 11 and (a + b) !
Step-by-step explanation:
Given a two digit number , the digits written in reverse order is
.
Note that a two digit number ab = 10a + b.
For example: 24 = 10(2) + 4
Similarly, ba = 10(b) + a
Now, the sum of the numbers ab and ba = 10a + b + 10b + a
= 11a + 11b
= 11(a + b)
Hence, the sum of any two digit number ab and the reverse of the number ba, is divisible by 11 and (a + b).
Hence, proved.
x = - 1
given = x + 3
square both sides
1 - 3x = (x + 3 )² ( expand right side using FOIL )
1 - 3x = x² + 6x + 9 ( subtract 1 - 3x from both sides )
0 = x² + 9x + 8
0 = ( x + 1)(x + 8)
equate each factor to zero and solve for x
x + 1 = 0 ⇒ x = -1
x + 8 = 0 ⇒ x = - 8
As a check
substitute these values into the equation and if both sides are equal then they are the solutions
x = - 1 : = 2 and - 1 + 3 = 2 ← true
x = - 8 : = 5 and - 8 + 3 = -5 ← false
thus the only solution is x = - 1