Find the square of leg b of the right tiangle a=2b and c=10

A^2+b^2=c^2
where c=25 m. and a=2b-10 m.
substitute
(2b-10)^2+b^2=25^2
4b^2-40b+100+b^2=625
5b^2-40b+100=625
divide both sides by 5
b^2-8b+20=125
subtract 20 from both sides
b^2-8b=105
complete the square
take half of 8 and square it=16
i hope this helps =3

Letter b hope it