[(x-0.6)+x][(x-0.6)-0.4]=1.56(x-0.6)^2-0.4(x-0.6)+x(x-0.6)-0.4x=1.56x^2-1.2x+0.36-0.4x+0.24+x^2-0.6x-0.4x=1.562x^2-2.6x+0.6=1.56x^2-1.3x-0.75=0
