Question 445399
shorter leg =x
longer leg = x+5
hyp=2x-5

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Apply Pythagoras theorem
x^2+(x+5)^2=(2x-5)^2
x^2+x^2+10x+25=4x^2-20x+25
group the terms
2x^2-30x=0
2x(x-15)=0
so x= 15 
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15^2+20 ^2= 625
(2x-5)^2= 625