Question

若有理数a.b满足l3a+1l+（2b-1)的2次方=0,求ab分之3a的2次方-2b的3次方要详细答案和过成

Answer 1

l3a+1l+（2b-1)的2次方=0

l3a+1l=0,（2b-1)的2次方=0

a=-1/3,b=1/2

(3a^2-2b^3)/ab

=[3*(-1/3)^2-2*(1/2)^3]/[(-1/3)*1/2]

=[3*1/9-2*1/8]/(-1/6)

=[1/3-1/4]/(-1/6)

=[1/3-1/4]*6

=(4/12-3/12)*6

=1/12*6

=1/2