Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
The area of square A is 25. The area of square B is 81. What's the length difference between the sides of square A and B?

### Response:
The area of a square is calculated as length * width. Because all a square has all sides equal then we can say that given a side S, the area is S*S
For square A of sides A, the area is A*A=25 or A=<<5=5>>5
For square B of sides B, the area is B*B=81 or B=9
The side difference is 9-5=<<9-5=4>>4
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