Answer:
8.80
Step-by-step explanation:
Answer: 
Step-by-step explanation:
Given
The unit cost is given by
find the derivative of the unit cost and equate it to zero to obtain the minimum value
Substitute 140 for 
in the cost function, we get
![C(140)=0.6[140]^2-168(140)+30,389\\C(140)=11,760-23,520+30,389\\C(140)=\$18,629](https://tex.z-dn.net/?f=C%28140%29%3D0.6%5B140%5D%5E2-168%28140%29%2B30%2C389%5C%5CC%28140%29%3D11%2C760-23%2C520%2B30%2C389%5C%5CC%28140%29%3D%5C%2418%2C629)
Here is the equation: x+(x+20) = 120
Since you can't combine anything yet, its x+x+20=120
You need to get x by itself
Minus 20 from both sides
Its x+x=100 now
Combine the x's which is now 2x
Now divide 100 by 2 which is 50
x=50
---------------
Lets check:
50+(50+20)=120
Now combine the numbers in the parentheses
Its now 50+70=120
50+70=120 and 70-50=20
As you can see, he ran 50 minutes the first day and 70 minutes the second day
Answer:
Step-by-step explanation:
5.73 – (-3.56)= 9.29
− 5/3 + 2 1/3= 2/3
Hello there! The cost of a cookie is $0.72.
Start by multiplying the cost of lunch by 5 and subtract that from the total to get rid of the cost of lunch.
$1.85 x 5 = $9.25
$20 - $9.25 = $10.75
So, there were FIVE students and each bough THREE cookies. To find the cost for each cookie, first divide the total spent on cookies by 5 to get what each student spent on cookies, then by 3 to see how much each cookie cost.
$10.75/5 = $2.15
$2.15/3 = 0.716666667, which can be rounded to $0.72.
I hope this helps and have a great rest of your day!
