(5x-1)*(5x+1/2)=0
25x²+2.5x-5x-0.5=0
25x²-2.5x-0.5=0
D=6.25+50=56.25=7.5²
x1=(2.5+7.5)/50=0.2
x2=(2.5-7.5)/50= -0.1
или
5х-1=0, 5х=1, х1=1/5=0.2
5х+0.5=0, 5х=-0.5, х= -0.1
проверка
(5*0.2-1)(5*0.2+0.5)=0
0=0
(5*(-0.1)-1)(5*(-0.1)+0.5)=0
-1.5*(-0.5+0.5)=0
0=0
ответ: х1=0.2; х2= -0.1