9514 1404 393
Answer:
   360
Step-by-step explanation:
Sam obtains a "contribution margin" of $0.50 -0.25 = $0.25 per cookie. That will cover the cost of baking supplies when he sells ...
   $90 / ($0.25/cookie) = 360 cookies
Sam needs to sell 360 cookies before he can start making a profit.
_____
If you like, you can find Sam's break-even point by equating revenue and cost. The is the number of cookies Sam must sell for a profit of 0, that is, for non-negative profit.
   P = R - C
   0 = R - C
   R = C
   0.50n = 90 +0.25n
   0.25n = 90 . . . . subtract 0.25n
   n = 90/0.25 = 360 . . . .divide by the coefficient of n
You may notice this is similar to our description above.
 
        
             
        
        
        
Answer:
1/2x+7
Step-by-step explanation:
 
        
             
        
        
        
Circular pen means you are going to use Area = Pi(r^2). 
So 78.5 = pi(r^2). Divide by pi on both sides to get r^2 = 78.5/pi. Take the square root of that to get r or radius = approximately 4.99. If you need an exact answer then use 

 for the next part because you are not done yet.
Plug whatever R you use into the circumference formula of Circumference = 2(pi)(r). 
If you use 4.99, you do 2(pi)(4.99) which is approximately 31.35. If you use the exact answer, you do 2(pi)(

) which gives you approximately 31.41. 
Either way you'll need about 31 meters of chicken wire but the 31.40796 or ~31.41 is closer to the exact answer. 
 
        
        
        
Answer:
Step-by-step explanation:
we can use the trigonometric function in a right triangle 
cos x = adjacent side to the angle /hypothenuse 
cos 36°= x/10  ; multiply both sides by 10 
10 * cos 36° = x ; make sure your calculator mode is in degrees
8.1  = x