Answer:
Step-by-step explanation:
let th numbers be x and y.
x+y=21
y=21-x
Product P=xy=x(21-x)=21 x-x^2
P'=21-2x
P'=0 gives 21-2x=0,x=21/2
P"=-2
which is less than 0 at x=21/2
so P is greatest at x=21/2
y=21-21/2=21/2
P=21/2 ×21/2=441/4=110.25
a. 14, 15, 17, 8
230 were sold at the door
170 were sold in advance
*i dont know if this is the proper way to do it but it has the correct answer
x=at door y=in advance
x+y=400
3x+2y=1030
y=-x+400
2y=-3x+1030
y=-3/2x+515
-x+400=-3/2x+515
x=230 y=170
<u>r=6</u>
3 = r/2
6 = r
C: Finance Charge
