(2ax+3)/(a-x)=3/4
->4(2ax+3)=3(a-x)
->8ax+12=3a-3x
->8ax-3a=-3x-12
->(8x-3)a=-3x-12
将x=1代入上式可得,
(8-3)a=-3*1-12
->5a=-15
->a=-3