The first selection can be any one of the 8.
For each one ...
The second selection can be any one of the remaining 7.
For each one ...
The third selection can be any one of the remaining 6.
For each one ...
The fourth selection can be any one of the remaining 5.
Total number of ways to select four = (8 x 7 x 6 x 5) = 1,680 ways
BUT ... There are not 1,680 different groups of 4 .
Each group of 4 can be selected in (4 x 3 x 2) = 24 different ways.
So, although there are 1,680 different ways to select 4 singers,
there are only
(1,680 / 24) = 70 different groups of 4
that you can end up with.
Answer:
16 centimetre square :p
Step-by-step explanation:
Answer:
4.5 cm
Step-by-step explanation:
The ruler says it all..... (why do you need help with this? What grade????)
Hope this helps, have a good day :)
Step-by-step explanation:
You can solve systems of equations using either substitution or elimination. For these problems, I recommend elimination. I'll do the first one as an example.
-3x + 16y = 9
-4x + 8y = 12
Multiply the second equation by -2.
8x − 16y = -24
Add to the first equation (notice the y's cancel out).
(-3x + 16y) + (8x − 16y) = 9 − 24
5x = -15
Solve for x.
x = -3
Now you can plug this into either equation to find y.
-3(-3) + 16y = 9
9 + 16y = 9
y = 0
The solution is (-3, 0).
