X1+x2=-4a, x1*x2=a^2 x1^2+x2^2=(x1+x2)^2-2x1*x2=2,24 (-4a)^2-2*a^2=2,24 16a^2-2a^2=2,24 14a^2=2,24 a^2=2,24:14=0,116 a=-0,4и а=0,4