(6-5х)^2-10х(2,5х+1)=8

36-60x+25x^2-25x^2-10x=8

-70x=-28

x=28/70=0.4

(6-5x)^2-10x(2,5x+1)=8
36-60x+25x^2-25x^2-10x-8=0

36-60x-10x-8=0

36-70x-8=0

28-70x=0

x=28/70

x=0.4