Answer:
495
Step-by-step explanation:
This problem can be solved b using a combination. We're using a combination for this because the order in which you would pick the books doesn't matter. To solve, we would plug in the number of books, in this case 12, into the n value of the combination. Then we would plug in the number of books that would be picked, in this case 4, into the r value of the combination. Solve the combination, and you get 495.
The solution depends on the value of

. To make things simple, assume

. The homogeneous part of the equation is

and has characteristic equation

which admits the characteristic solution

.
For the solution to the nonhomogeneous equation, a reasonable guess for the particular solution might be

. Then

So you have


This means


and so the general solution would be
Answer:
5unit
Step-by-step explanation: since area of rectangle = length*width
Here length is (x+2) and width is(2x+3)
(x+2)(2x+3)=91
On further solving
2x^2+75x-85=0
2x^2-10x+17x-85=0
2x(x-5)+17(x-5)=0
(2x+17)(x-5)=0
x=5unit
You sure that’s the radius and not diameter? But if it is, the volume would be 70,276.2 cm
I think it is 78 I hope is help you :)