Solution:
Suppose that one side of a square is X and the other side is 2x- 10.
x? +(2x- 10)? = 100
x? +4x? -40x+ 100= 100
5x? -40x=0
5x(x-8)=0
5x=0 or x-8=0.
So X 1=0, X2=8.
Because the side length is an integer, the root 0 is truncated.
Then x=8.
The other side length =2×8- 10=6.
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