Answer: 16⅔ yds by 25 yds
Step-by-step explanation:
Let x be the length of 3 fence sections
Let y be the length of 2 fence sections
A = xy
3x + 2y = 100
y = 50 - 1.5x
A = x(50 - 1.5x) = 50x - 1.5x²
dA/dx = 50 - 3x
0 = 50 - 3x
3x = 50
x = 50/3 = 16⅔ yds
y = 50 - 1.5(16⅔) = 25 yds