C because you have to think a bout how to get from y to x
Answer:
120
Step-by-step explanation:
Since we're dealing with a problem where the order matters and the first two letters are already chosen we need to subtract the number of letters and the number of available slots per group.
We use the permutation formula to find the answer, but before that let's check values.
n = 8
k = 5
Now since there are two letters already chosen we have to deduct two from both the value of n and k.
n = 6
k = 3
Now we can use the permutation formula:




The 3*2*1 cancels out and leaves us with:


So there are 120 possible ways to arrange eight letters into groups of five where order matters and the first two letters are already chosen.
Answer:
C.
Step-by-step explanation:
Hi there!
To answer this, we must set it up as

Now we just use the distributive property to solve.
this becomes 
I hope this helps!
Answer:
<h2>
-29.61m/s</h2>
Step-by-step explanation:
Given the distance of fall of the student in term of the time t expressed by the equation s(t) = −16t² + 8√t, to get the average speed of fall of the pencil after 2.8 secs, we will need to differentiate the given function first since Velocity is the change in distance of a body with respect to time i.e
V = d(s(t))/dt
s(t) = −16t² + 8t^1/2
V = -32t+1/2(8)t^(1/2 - 1)
V = -32t+4t^-1/2
The average speed of the fall Using the fact that the pencil hit the ground in exactly 2.8 seconds, will be gotten by substituting t = 2.8 into the resulting equation.
V = -32t+4(2.8)^-1/2
V = -32t+4/√2.8
V = -32+4/1.6733
V = -32+2.391
v = -29.61m/s
<em>Hence the average speed of the fall is -29.61m/s</em>