一道二元二次方程组3(6-a)=(5a/2)(4-b)a/3=(4-b)/b

3(6-a)=(5a/2)(4-b),18-3a=10a-5ab/2,13a-5ab/2=18,a(13-5b/2)=18
a/3=(4-b)/b,ab=12-3b,a=(12-3b)/b
((12-3b)/b)*(13-5b/2)=18
(12-3b)*(26-5b)=36b
15b^2-60b-78b+312=36b
15b^2-174b+312=0
b1=(174+(174^2-4*15*312)^0.5)/30=(174+(11556)^0.5)/30=5.8+(12.84)^0.5
b2=(174-(174^2-4*15*312)^0.5)/30=(174-(11556)^0.5)/30=5.8-(12.84)^0.5
a1=(12-3b1)/b1=(12-17.4-3*(12.84)^0.5)/(5.8+(12.84)^0.5)=(-5.4-3*(12.84)^0.5)/(5.8+(12.84)^0.5)
a2=(12-3b2)/b2=(12-17.4+3*(12.84)^0.5)/(5.8-(12.84)^0.5)=(-5.4+3*(12.84)^0.5)/(5.8-(12.84)^0.5)