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

question:

could we have options?

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13