1)х^2=-9х-8 2)6х^2-12х=0 3)4х^2-1=0 арефметическая прогрессия? 13,9,

1) x^2 + 9x + 8 = 0
D = 49;x1 = -1;x2 = -8;
2)6x^2 - 12x =0;
6x(x-2) = 0;
x1 = 0;x2 = 2;
3)4x^2 - 1=0
4x^2 = 1;
x^2 = 1/4;        x1 = +1/2;    x2 = -1/2;