You add 25 to both sides.
You take half the x term, which is 10/2=5, and square it, so 25.
I'm not sure if this is correct but I made this into the equation 61.5=17+2.5x. I solved the equation and the answer I got is 17.8%
Refer to the diagram shown below.
The height of the pole is CD (3 m), and its shadow is AB (1.22 m).
The height of the building is h m, and its shadow is AD (38.5 m).
The two triangles ΔABC and ΔADE are similar because of AAA.
Therefore

Cross multiply.
1.22 h = 3*38.5 = 115.5
h = 115.5/1.22 = 140.91 m
Answer: 141 m (nearest meter)
So basically 3cm is the model and 2 m is the actual size. So the hood is 1m so it is half of 2m which means the answer to the question is 1.5cm