<u>We are given:</u>
The time-traveller has 79 books, but he can only take 5 books
since we need to find the number of ways he can choose 5 books, we know that the order in which he takes the books does NOT matter
Hence, we will use combination
<u>Finding the number of ways:</u>
Since we will use combination, ₇₉C₅
We know that the formula for combination is (n!) / (r!(n-r)!)
₇₉C₅ = 79! / 5!(74!)
₇₉C₅ = 22,537,515
Therefore, the time traveller can choose 5 books in 22,537,515 different ways
Answer:
<em>The correct option is C.</em>
Step-by-step explanation:
<u>Root Of Complex Numbers</u>
If a complex number is expressed in polar form as
Then the cubic roots of Z are
![\displaystyle Z_1=\left(\sqrt[3]{r},\frac{\theta}{3}\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_1%3D%5Cleft%28%5Csqrt%5B3%5D%7Br%7D%2C%5Cfrac%7B%5Ctheta%7D%7B3%7D%5Cright%29)
![\displaystyle Z_2=\left(\sqrt[3]{r},\frac{\theta}{3}+120^o\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_2%3D%5Cleft%28%5Csqrt%5B3%5D%7Br%7D%2C%5Cfrac%7B%5Ctheta%7D%7B3%7D%2B120%5Eo%5Cright%29)
![\displaystyle Z_3=\left(\sqrt[3]{r},\frac{\theta}{3}+240^o\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_3%3D%5Cleft%28%5Csqrt%5B3%5D%7Br%7D%2C%5Cfrac%7B%5Ctheta%7D%7B3%7D%2B240%5Eo%5Cright%29)
We are given the complex number in rectangular components
Converting to polar form
It's located in the second quadrant, so
The number if polar form is
Its cubic roots are
![\displaystyle Z_1=\left(\sqrt[3]{2},\frac{120^o}{3}\right)=\left(\sqrt[3]{2},40^o\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_1%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C%5Cfrac%7B120%5Eo%7D%7B3%7D%5Cright%29%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C40%5Eo%5Cright%29)
![\displaystyle Z_2=\left(\sqrt[3]{2},40^o+120^o\right)=\left(\sqrt[3]{2},160^o\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_2%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C40%5Eo%2B120%5Eo%5Cright%29%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C160%5Eo%5Cright%29)
![\displaystyle Z_3=\left(\sqrt[3]{2},40^o+240^o\right)=\left(\sqrt[3]{2},280^o\right)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20Z_3%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C40%5Eo%2B240%5Eo%5Cright%29%3D%5Cleft%28%5Csqrt%5B3%5D%7B2%7D%2C280%5Eo%5Cright%29)
Converting the first solution to rectangular coordinates
![z_1=\sqrt[3]{2}(\ cos40^o+i\ sin40^o)](https://tex.z-dn.net/?f=z_1%3D%5Csqrt%5B3%5D%7B2%7D%28%5C%20cos40%5Eo%2Bi%5C%20sin40%5Eo%29)
The correct option is C.
Step-by-step explanation:
The price of machine=$50000
depreciates rate (R )=1/4×100%
=25%
x = -25
<u>+25+25
</u>x + 25 = 0
<u>5(x+25) = 5(0)
</u>5x +125 = 0<u>
</u><u>
</u>
3x + 2y=-10 equation 1
y=-x -4 equation 2
use the substitution method of elimination to get the answer to the question.
*using substitution
substitute equation 2 in one and we get
3x +2(-x-4)=-10
3x- 2x-8=-10
x=-2 and y=-2
Answer:
B
