Let the integers be x-1, x, x+1.
Given,
x -1 + x + x + 1 = 21 + 2(x - 1)
3x = 21 + 2x - 2
x = 19
Hence, the three integers are 18, 19 and 20.
If order matters, then there are 12 ways to do this
If order does not matter, then there are 6 ways to do this
===========================================
We have 4 choices for the first slot and 3 choices for the next (we can't reuse a letter) so that's where 4*3 = 12 comes from
If order doesn't matter, then something like AB is the same as BA. So we are doubly counting each possible combo. To fix this, we divide by 2: 12/2 = 6
To be more formal, you can use nPr and nCr to get 12 and 6 respectively (use n = 4 and r = 2)
The answer is 456
This the answer 456
Answer:
C
Step-by-step explanation:
Solve the quadratic in answer choice C using the quadratic formula:
.
Here a=1, b=2, and c=17.
Substitute and you'll have:
