6^2 is the correct answer
Primary equation: A(x)= (5y)(3X)
Secondary equation: 5y+3X=1000
y=200-(3X)/5
A(x)=3X(1000-3X)
A(x)=3000X-9X²
Now, find the derivative of A(x) to find the max... here's the work for that, or you could guess and check.
A'(x)=3000-18X
Set derivative equal to 0
0=3000-18X
166.6666666=X
Now test the intervals
(0,166.6666) (166.66666, 1000)
1st derivative is + 1st derivative is -
Plug the X value back into the secondary equation
5y+3(166.666666)=1000
5Y=500
Y=5
Answer:
X= 166.6666666666
Y=5
Please note, this is entry level calculus, and your teacher may expect you to use a different, longer route such as guess and check.
8/1/2=10/n=2*(n-15)/3n*3n=0*3n. Now we do, 2*(n-15)=0, which gives us 2=0. N-15=0. So n=15. Therefore, the answer is n=15.
