If order matters, then there are 12 ways to do this
If order does not matter, then there are 6 ways to do this
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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)
Answer:
x = - 3
y = 4
Step-by-step explanation:
x + y = 1 | (-3)
x + 3y = 9
- 3x - 3y = - 3
x + 3y = 9
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- 3x + x = 9 - 3
- 2x = 6
2x = - 6
x = - 3
- 3 + y = 1
y = 1 + 3
y = 4
I need help with that one too.
Answer:
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Step-by-step explanation: