1) x^2-2x+10=0 2) 3x^2-7x-1=0
X^2 - 2X + 10 = 0 D = 4 - 4*1*10 = 4 - 40 = ( - 36 ) D < 0 корней нет ==================== 3X^2 - 7X - 1 = 0 D = 49 -4*3*(-1) = 49 + 12 = 61 V D = V 61 X1 = ( 7 + V 61 ) : 6 = 7/6 + 1/6 V 61 X2 = 7/6 - 1/6 V 61