Answer: 10
Imagine you have 2 slots or boxes that are empty. They represent the possible choices for the letter you pick. For example, you can place B in slot 1 and D in slot 2. There are 5 choices for slot 1 (A,B,C,D,E) and four choices for slot 2. Why 4? Because after we pick the letter for slot 1, we have one less letter to pick from. We can't reuse that letter.
Now multiply those values 5 and 4 to get 20. There are 20 different ways to pick a pair of letters from a pool of 5 total. However, order does NOT matter because the segment AB is the same as BA. Since order doesn't matter, we are doubly counting when we shouldn't. In other words, our count is two times higher than it should be. Instead of 20 pairs, it's actually 20/2 = 10 pairs. That's why the answer is 10.
The list of 10 segments are: {AB,AC,AD,AE,BC,BD,BE,CD,CE,DE}
Side note: you can use the nCr combination formula with n = 5 and r = 2 to get the same answer.
Answer:
28 hours
Step-by-step explanation:
6x28=168
I would say all real numbers as the domain for this would be (-∞,∞).
However, I may be wrong, math is not my strong suit.
To find the first blank, just replace x in the equation with 12 and solve.
a(12) = 50 - 1.25(12) = your answer for blank 1
For blank 2: because x represents the number of apps on her phone, and x is given 12 for this problem, she bought 12 apps.
For blank 3: You would mention how many apps she got twice, so not the first option or the third option. It should be the answer from the first blank because the equation represents how much money is in her account.
Answer:
-20/7
Step-by-step explanation:
5m +72 = -2m + 52
5m + 2m = 52-72
7m = -20
m = -20/7
