Разложить кв трехчлен(через дескреминант) x-степень 3x2+0.9x-2.1=0 a=3 b=0.9 c=-2.1

D= 0.9^2-4*3*(-2.1)=0.81+25.2=26.01=5.1

x1=-0.9+5.1/6=0.7

x2=-0.9-5.1/6=-1

3x^2+0.9x-2.1=(x-0.7)(x+1)

3*x*2+0.9*x-2.1 = 0*a , 0*a = 3*b , 3*b = 0.9*c , 0.9*c = - 2.1*d , - 2.1*d = b*2-4*a*c

6.9x - 2.1 = 0.0 = 3b, 3b = 0.9c, 0.9c = - 2.1d, -2.1d = 2b - 4ac

23x = 7

a = r, b = 0, c = 0, d = 0, x = 0.304347826086957;  r R