If x is the number of berries you can buy with 1 dollar,
1 pound of blueberries = $4.00
x pound of berries = $1.00
Lets set up a proportion- because these are directly proportional- when there is more pounds of berries, it will cost more.
Cross multiply
4x=1
Divide both sides by 4 to isolate x
x=1/4 or $0.25
5cos (2x)+7=cos (2x)+8, 4cos (2x)=1, cos (2x)=1/4, 2x=arccos(1/4), x=(1/2)arccos (1/4). I used x instead of theta, and arccos is cos inverse
Answer:
k = - 2
Step-by-step explanation:
Given α and β are the zeros of x² - 6x + k = 0 , with
a = 1, b = - 6 and c = k , then
α + β = - 
= - 
= 6
αβ = 
= 
= k
Then solving
(α + β)² - 2αβ = 40
6² - 2k = 40
36 - 2k = 40 ( subtract 36 from both sides )
- 2k = 4 ( divide both sides by - 2 )
k = - 2
