2(a+3)+3(2a-1)
=2a+6+6a-3
=8a+3
#6 is incorrect
it's 6 7/8
#7 is correct
Answer:


Step-by-step explanation:
Given

Solving (a):
Find k
To solve for k, we use the definition of joint probability function:

Where

Substitute values for the interval of x and y respectively
So, we have:

Isolate k

Integrate y, leave x:
![k \int\limits^2_{0} y {dx} \, [0,x/2]= 1](https://tex.z-dn.net/?f=k%20%5Cint%5Climits%5E2_%7B0%7D%20y%20%7Bdx%7D%20%5C%2C%20%5B0%2Cx%2F2%5D%3D%201)
Substitute 0 and x/2 for y


Integrate x
![k * \frac{x^2}{2*2} [0,2]= 1](https://tex.z-dn.net/?f=k%20%2A%20%5Cfrac%7Bx%5E2%7D%7B2%2A2%7D%20%5B0%2C2%5D%3D%201)
![k * \frac{x^2}{4} [0,2]= 1](https://tex.z-dn.net/?f=k%20%2A%20%5Cfrac%7Bx%5E2%7D%7B4%7D%20%5B0%2C2%5D%3D%201)
Substitute 0 and 2 for x
![k *[ \frac{2^2}{4} - \frac{0^2}{4} ]= 1](https://tex.z-dn.net/?f=k%20%2A%5B%20%5Cfrac%7B2%5E2%7D%7B4%7D%20-%20%5Cfrac%7B0%5E2%7D%7B4%7D%20%5D%3D%201)
![k *[ \frac{4}{4} - \frac{0}{4} ]= 1](https://tex.z-dn.net/?f=k%20%2A%5B%20%5Cfrac%7B4%7D%7B4%7D%20-%20%5Cfrac%7B0%7D%7B4%7D%20%5D%3D%201)
![k *[ 1-0 ]= 1](https://tex.z-dn.net/?f=k%20%2A%5B%201-0%20%5D%3D%201)
![k *[ 1]= 1](https://tex.z-dn.net/?f=k%20%2A%5B%201%5D%3D%201)

Solving (b): 
We have:

Where 

To find
, we use:

So, we have:



Integrate x leave y
![P(x > 3y) = \int\limits^2_0 x [0,y/3]dy](https://tex.z-dn.net/?f=P%28x%20%3E%203y%29%20%3D%20%5Cint%5Climits%5E2_0%20%20x%20%5B0%2Cy%2F3%5Ddy)
Substitute 0 and y/3 for x
![P(x > 3y) = \int\limits^2_0 [y/3 - 0]dy](https://tex.z-dn.net/?f=P%28x%20%3E%203y%29%20%3D%20%5Cint%5Climits%5E2_0%20%20%5By%2F3%20-%200%5Ddy)

Integrate
![P(x > 3y) = \frac{y^2}{2*3} [0,2]](https://tex.z-dn.net/?f=P%28x%20%3E%203y%29%20%3D%20%5Cfrac%7By%5E2%7D%7B2%2A3%7D%20%5B0%2C2%5D)
![P(x > 3y) = \frac{y^2}{6} [0,2]\\](https://tex.z-dn.net/?f=P%28x%20%3E%203y%29%20%3D%20%5Cfrac%7By%5E2%7D%7B6%7D%20%5B0%2C2%5D%5C%5C)
Substitute 0 and 2 for y




Answer:
negative.
Step-by-step explanation:
what is half of -6?
=-3, negative.
You owe your friend 6 dollars, and you have 0 dollars.
Your friend told you: you only have to pay half the money
so, instead of owing 6 dollars, you owe 3 dollars, which will still be equal to -3 dollars from your wallet :)
For this case we must find the product of the following expression:
![\sqrt [3] {5} * \sqrt {2}](https://tex.z-dn.net/?f=%5Csqrt%20%5B3%5D%20%7B5%7D%20%2A%20%5Csqrt%20%7B2%7D)
By definition of properties of powers and roots we have:
![\sqrt [n] {a ^ m} = a ^ {\frac {m} {n}}](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%20%5E%20m%7D%20%3D%20a%20%5E%20%7B%5Cfrac%20%7Bm%7D%20%7Bn%7D%7D)
We rewrite the expression using the lowest common index of 6, then:

We rewrite the terms in an equivalent way:

We rewrite the expression using the property mentioned:
![\sqrt [6] {5 ^ 2} * \sqrt [6] {2 ^ 3} =](https://tex.z-dn.net/?f=%5Csqrt%20%5B6%5D%20%7B5%20%5E%202%7D%20%2A%20%5Csqrt%20%5B6%5D%20%7B2%20%5E%203%7D%20%3D)
We combine using the product rule for radicals:
![\sqrt [n] {a} * \sqrt [n] {b} = \sqrt [n] {ab}](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%7D%20%2A%20%5Csqrt%20%5Bn%5D%20%7Bb%7D%20%3D%20%5Csqrt%20%5Bn%5D%20%7Bab%7D)
So:
![\sqrt [6] {5 ^ 2 * 2 ^ 3} =\\\sqrt [6] {25 * 8} =\\\sqrt[6]{200}](https://tex.z-dn.net/?f=%5Csqrt%20%5B6%5D%20%7B5%20%5E%202%20%2A%202%20%5E%203%7D%20%3D%5C%5C%5Csqrt%20%5B6%5D%20%7B25%20%2A%208%7D%20%3D%5C%5C%5Csqrt%5B6%5D%7B200%7D)
ANswer:
Option b