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777dan777 [17]
3 years ago
14

NCr/nPr=r! give proof.

Mathematics
1 answer:
Sergio [31]3 years ago
3 0
<span>It's 1/r! 

nCr = n! / r!(n-r)! 
nPr = n! / (n-r)! 

If you divide the two you'd have: 

n! / r! (n-r)! * (n-r)! / n! = 1/r!

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
</span>
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Given: AB tangent to circle O at B, and secant through point A intersect the circle at points C and D. Find CD, if
azamat

Answer:

6 cm

Step-by-step explanation:

If you use Tangent-secant product (chapter reference), AB/AC = AD/AB so 4/2 = AD/4. AD = 8, CD = AD - AC = 8 - 2 = 6 cm.

3 0
3 years ago
Read 2 more answers
joe has a piggy bank with $8.90 split upon nickels, dimes, and quarters. The piggy bank contains 76 coins in all. The number of
kozerog [31]

Answer:

There are 38 dimes, 22 nickels and 16 quarters.

Step-by-step explanation:

Let n, d and q represent the # of nickels, dimes and quarters respectively.

Then n + d + q = 76

The value of a nickel is $0.05; that of a dime is $0.10, and that of a quarter is $0.25.

Thus, the value of n nickels is $0.05n (and so on).

The total value of the coins is $0.05n + $0.10d + $0.25q = $8.90.

d = n + q allows us to eliminate d.

First, n + d + q = 76 becomes n + (n + q) + q = 76, and second:

$0.05n + $0.10(n + q) + $0.25q = $8.90.  Here we have succeeded in eliminating d from two different equations, and now we have these two different equations in two unknowns (n and q), which is solvable.

Simplifying both equations, we get:

2n + 2q = 76 and

5n + 10n + 10q + 25q = 890, or 15n + 35q = 890

Let's use the substitution method of solving linear equations:

Rewrite 2n  + 2q = 76 as n + q = 38, or n = 38 - q.  Substituting this result into the second equation, we get:

15(38 - q) + 35 q = 890, or

  570 - 15q + 35q = 890, or

   570 + 20 q = 890.  Then 20q = 890 - 570 = 320, and q = 320/20 = 16.

There are 16 quarters.  Thus, the number of nickels is n = 38 - 16 = 22.

Finally, since n + d + q = 76, 22 + d + 16 = 76, or:

22 + d = 60, or d = 60 - 22 = 38.

There are 38 dimes, 22 nickels and 16 quarters.

4 0
3 years ago
How do I solve this ?
boyakko [2]
(1,-2) im pretty sure is the answer
8 0
3 years ago
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What is the initial value of the function represented by this graph?
ohaa [14]

Answer:

its 6 I'm pretty sure about it

8 0
3 years ago
15. Sofie bought a desk for $45 that was
Alchen [17]

Answer:

10%

Step-by-step explanation:

50+50=100

45+45=90

100-90=10

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2 years ago
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