已知关于x的方程x/2-x=-a的解是方程(2/3)x-(1/12)*9(x+16）=(1/2)x-a的解的1/3,求a的值.

x/2-x=-a的解=>-x/2=-a => x=2a
=> 6a是(2/3)x-(1/12) *9（x+16）=(1/2)x-a的解
=>(2/3)*6a -(3/4)(6a+16)=(1/2)*6a -a
=> 4a -(9/2)a -12=2a
=> (4- 9/2 -2)a=12 => (-5/2)a=12
=> a=-24/5...ans