I hope this helps you
if 2 cm 21 km
9cm ? km
?×2=9×21
?=189÷2
?=94,5 km
Answer:
Therefore the width is 25 feet for getting maximum area.
The maximum area of the rectangle is 625 square feet.
Therefore the range is 0≤A≤625.
Step-by-step explanation:
Given function is
A = - x²+50x
We know that ,
If y = ax²+bx+c
For the maximum 
Here a = -1 , b= 50 and c=0
Therefore the width 
Therefore the width is 25 feet for getting maximum area.
The maximum area =[ -(25)²+50.25] square feet
= 625 square feet
The area can not be negative and maximum area is 625 square feet.
Therefore the range is 0≤A≤625.