An apple farm yields an average of bushels of apples per tree when trees are planted on an acre of ground. Each time 1 more tree is planted per acre, the yield decreases by 1 bushel (bu) per tree as a result of crowding. How many trees should be planted on an acre in order to get the highest yield?

33 trees

Step-by-step explanation:

Let us assume the number of trees planed for receiving greatest yield is be x

Now the equation would be

f(x) = (21 + x) (45 - x)

= -x^2 + 24x + 945

Now we have to differentiate the f with regard to x

Now as it can be seen that

f is at maximum when x = 12

So, the number of trees would be

= 21 + 12

= 33 trees

could you reply to this with the question so i can ?

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)