1/2 of 20 is 20/2 which is 10.
All you really need to do here is to divide 20 by 2 to get 10.
Answer:
13.20 teaspoon of fertiliser needed for entire garden.
Step-by-step explanation:
Diameter of the garden = 14.50 ft
Radius of the garden = 7.25 ft
Area
[tex]A=\pi r^2[/text]
[tex]A=\pi \times 7.25 \times 7.25[/text]
[tex]\pi=3.14[/text]
[tex]A=\pi \times 7.25 \times 7.25[/text]
[tex]A=3.14 \times 7.25 \times 7.25[/text]
Hence
[tex]A=165.046[/text]
Area is 165.046 Sq Ft
For 25 sq ft of fields the fertiliser needed = 2 tea spoon
For 1 sq ft of fields the fertiliser needed =
[tex]\frac{2}{25}[/text] tea spoon
For 165.046 sq ft of fields the fertiliser needed =
[tex]\frac{2 \times 165.046 }{25}[/text] tea spoon
For 165.046 sq ft of fields the fertiliser needed = 13.20 tea spoon
The new square has length: 10 + l, where l is the original length of the square, and it's area is (10 + l)^2;
So, we solve the equation: 3 x l^2 = (10 + l)^2;
Then, 3 x l^2 = 100 + 20 x l + l^2;
Finally, 2xl^2 - 20xl - 100 = 0; / ÷2;
l^2 - 10l - 50 = 0 (we use the quadratic equation formula);
The only positive solution is l = 5(1+ \sqrt{3} );
