四元二次方程组求解a+c=2b+d+ac=-27bc+ad=-44bd=7联立

一共六组解,如下：
{a -> 1.60329,b -> -0.255657,c -> 0.396715,d -> -27.3804},
{a -> 5.2886,b -> -0.794223,c -> -3.2886,d -> -8.81364},
{a -> -3.2886,b -> -8.81364,c -> 5.2886,d -> -0.794223},
{a -> 0.396715,b -> -27.3804,c -> 1.60329,d -> -0.255657},
{a -> 7.18417,b -> 9.50767,c -> -5.18417,d -> 0.736248},
{a -> -5.18417,b -> 0.736248,c -> 7.18417,d -> 9.50767}