Answer:
y=1
Step-by-step explanation:
4(1+2y)=12y
4*1 + 4*2y=12y
4 + 8y=12y
4=12y - 8y
4=4y
4/4=y
1=y
Answer:
5 pounds
Step-by-step explanation:
Given that:
Amount of gift card = $80
Cost of coffee per pound = $8.24
Amount left in the card = $38.80
To find:
Number of pounds of coffee bought = ?
Solution:
Let the number of pounds of the coffee bought = 
pounds
Cost of 1 pound = $8.24
Cost of pounds = $8.24 
Writing the equation as per question statement:
Therefore, 5 pounds of coffee was bought.
Since both is equal to p(a), you can set them as equal to each other:
15 = 2a - 3
18 = 2a
9 = a
So Volume of cylinder is pi*r^2*h = 1,000
Then lightest one means you have the smallest surface area. Which is one base and then the area of the surface. SA = pi*r^2 + 2pi*r*h
So now you have 2 equations, so:
h = 1,000/(pi*r^2)
So then SA = pi*r^2 + 2pi*r*(1,000/(pi*r^2) = pi*r^2 + 2,000/r
Derivative of SA is then 2pi*r -2,000/r^2. Set to 0
2pi*r-2,000/r^2 =0 --> 2pi*r^3 = 2,000 --> r^3 = 1,000/pi --> r = 10/pi^(1/3)
Now go back to the volume function: pi*r^2*h =1,000 --> 1,000/(pi*100/pi^(2/3)) = h
<span>h = 10 / pi^(1/3)</span>
