Option C 40-2 x
150 square feet
Step-by-step explanation:
Step 1 :
Given that the 3 sides, a,b, and x will be made of 40 feet of fencing,
we have a + b + x = 40
Since this is a rectangular garden , b= x
substituting b= x, we have a + x + x = 40
=> a+2 x = 40
=> a= 40-2 x
Step 2 :
To find the area in square feet,
when x = 15, a = 40 - 2 * 15 = 40-30 = 10 feet
The length and breadth of the rectangular garden are therefore 5 and 10 feet respectively
Hence, the area of the garden = length * breadth = 15 * 10 = 150 square feet