Let's call the stamps A, B, and C. They can each be used only once. I assume all 3 must be used in each possible arrangement.
There are two ways to solve this. We can list each possible arrangement of stamps, or we can plug in the numbers to a formula.
Let's find all possible arrangements first. We can easily start spouting out possible arrangements of the 3 stamps, but to make sure we find them all, let's go in alphabetical order. First, let's look at the arrangements that start with A:
ABC
ACB
There are no other ways to arrange 3 stamps with the first stamp being A. Let's look at the ways to arrange them starting with B:
BAC
BCA
Try finding the arrangements that start with C:
C_ _
C_ _
Or we can try a little formula; y×(y-1)×(y-2)×(y-3)...until the (y-x) = 1 where y=the number of items.
In this case there are 3 stamps, so y=3, and the formula looks like this: 3×(3-1)×(3-2).
Confused? Let me explain why it works.
There are 3 possibilities for the first stamp: A, B, or C.
There are 2 possibilities for the second space: The two stamps that are not in the first space.
There is 1 possibility for the third space: the stamp not used in the first or second space.
So the number of possibilities, in this case, is 3×2×1.
We can see that the number of ways that 3 stamps can be attached is the same regardless of method used.
C is your answer. Because 8 times 1.75$ = $14.00 and 5 times 1.25= $6.25. So $14.00+ $6.25 = $20.25
20 Answer: a₁ = 4
<u>Step-by-step explanation:</u>
21 Answer: n = 13
<u>Step-by-step explanation:</u>
22 Answer: n = 5
<u>Step-by-step explanation:</u>
Step-by-step explanation:
let's simply do the multiplications and then compare with the original.
(x-m)² + n
right ?
or is it
let's go for the first.
x² - 2mx + m² + n = x² - 3x
-2mx + m² + n = -3x
fun there we see two things :
-2m = -3
m = 3/2
and
m² + n = 0
(3/2)² = -n
9/4 = -n
n = -9/4
so our transformed expression looks like
(x - 3/2)² - 9/4
Answer:
Let's simplify step-by-step.
(−a)(−4 − 5a) − 3a(2 + a)
Distribute:
= (−a)(−4) + (−a)(−5a) + −3a^2 + −6a
= 4a + 5a^2 + −3a^2 + −6a
Combine Like Terms:
= 4a+5a^2 + −3a^2+ −6a
= (5a2+ −3a^2) + (4a + −6a)
= 2a2 + −2a
Final Answer:
= 2a^2−2a!
