3 years ago

What is the number of combinations of 7 things taken 3 at a time?

Mathematics

1 answer:

Helga [31]3 years ago

7 0

$C_7^3=\dfrac{7!}{3!4!}=\dfrac{5\cdot6\cdot7}{2\cdot3}=35$

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Solve the system, or show that it has no solution. (If there is no solution, enter NO SOLUTION. If there are an infinite number

liberstina [14]

Answer:

The system has an infinite set of solutions $(x,y) = (x, \frac{x-5}{4})$

Step-by-step explanation:

From the first equation:

$20x - 80y = 100$

$20x = 100 + 80y$

$x = \frac{100 + 80y}{20}$

$x = 5 + 4y$

Replacing on the second equation:

$-14x + 56y = -70$

$-14(5 + 4y) + 56y = -70$

$-70 - 56y + 56y = -70$

$0 = 0$

This means that the system has an infinite number of solutions, considering:

$x = 5 + 4y$

$4y = x - 5$

$y = \frac{x - 5}{4}$

The system has an infinite set of solutions $(x,y) = (x, \frac{x-5}{4})$

8 0

3 years ago

What is the answer to 22 +10X=

Nuetrik [128]

Complete question:

what is the answer to 22 +10x = 0

Answer:

the value of x is -2.2

Step-by-step explanation:

Given;

22 +10x = 0

collect like terms

10x = 0 - 22

10x = -22

divide both sides by 10

$\frac{10x}{10} = \frac{-22}{10} \\\\x = -2.2$

Therefore, the value of x is -2.2

6 0

3 years ago

PL has endpoints P(4, −6) and L(−2, 1).

masya89 [10]

I believe it'd be the one with the smiley emoji

6 0

3 years ago

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Evaluate the expression 5(8y+3r-5z) if r=3,y=5/8,and z=2

snow_lady [41]

First you plug in the missing values
5(8×5/8+3×3-5×2) = 20

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3 years ago

Which expression converts 4pi radians to degrees?

grin007 [14]

4pi/2pi = x/360
use a proportion
2 radians equals 360 degrees
x = 720 degrees

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3 years ago

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