求解18元一次方程组,急
0.25a1+0.6667b1+0.375c1=0.84
0.3125a2+0.1875b2+0.4018c2=0.34
0.3438a3+0.1964b3+0.4125c3=1.12
0.3625a4+0.2014b4+0.4183c4=0.18
0.375a5+0.2045b5+0.0703c5=Z
0.1875a1+0.125a2+0.09375a3+0.075a4+0.0046875a5=1.36
0.2917b1+0.175b2+0.125b3+0.09722b4+0.07955b5=X
0.34375c1+0.125c2+0.0875c3+0.06731c4+0.0546875c5=Y
X+Y=0.12
a1+a2+a3+a4+a5+b1+b2+b3+b4+b5+c1+c2+c3+c4+c5+0.1113=99.9
0.375*(a1+a2+a3+a4+a5)+0.25b1+0.3b2+0.32143b3+0.3333b4+0.34091b5+0.1875c1+0.2679c2+0.3c3+0.3173c4+0.328125c5+1.2857*(39.66-Z)+0.0313=56.2
求解a1-a5,b1-b5c1-c5,XYZ这18个参数的值,能化简用其中几个代替也行.