Answer:
Combinations:
A committee consisting of three members with the same role
Selecting two sandwiches from a menu of 10
Step-by-step explanation:
A combination is a selection of items from a collection, such that the order of selection does not matter.
A permutation is a selection of items from a collection, such that the order of selection matters.
A. The PIN for a bank or credit card - order matters → permutation
B. A committee consisting of three members with the same role - order does not matter → combination
C. A committee consisting of a president, vice president, and secretary - order matters → permutation
D. Final standings in a professional sports league - order matters → permutation
E. Selecting two sandwiches from a menu of 10 - order does not matter → combination
Answer:
![x=2+\frac{1}{2}\sqrt[]{21}](https://tex.z-dn.net/?f=x%3D2%2B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%5B%5D%7B21%7D)
or
Step-by-step explanation:
Add 21 on both sides.
a=4
b=-16
c=-5
![x=\frac{-b\frac{+}{}\sqrt[]{b^2-4ac} }{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%20%20%7D%7B2a%7D)
![x=\frac{-(-16)\frac{+}{}\sqrt[]{(-16)^2-4(4)(-5)} }{2(4)}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-%28-16%29%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B%28-16%29%5E2-4%284%29%28-5%29%7D%20%20%7D%7B2%284%29%7D)
![x=\frac{16\frac{+}{}\sqrt[]{256+80} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B256%2B80%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{336} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B336%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{2^2*2^2*21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B2%5E2%2A2%5E2%2A21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}2*2\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D2%2A2%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}4\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D4%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
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![x=\frac{16}{8}+\frac{4\sqrt[]{21}}{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D%2B%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D)
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![x=\frac{16}{8}-\frac{4\sqrt[]{21}}{8}\\x=2-\frac{1}{2}\sqrt{{21}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D-%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D%5C%5Cx%3D2-%5Cfrac%7B1%7D%7B2%7D%5Csqrt%7B%7B21%7D)
Answer:
(-4,-2)
x=-4
y=-2
Step-by-step explanation:
-3x-4y=20
3(x-10y=16)=3x-30y=48
The reason I multiplied 3 to the second equation is for when we add the equations together the x will cancel out.
-3x-4y=20
+ <u>3x-30y=48</u>
-34y=68
Divide -34 from both sides.
y=-2
To find x you need to plug in -2 for y into one of the equations.
x-10y=16
x-10(-2)=16
Remember a negative times a negative equals a positive.
x+20=16
Subtract 20 from both sides.
x=-4
Hope this helps!
If not, I am sorry.
