post tax prices

[ahlashi]

in a competitive mkt
Qd=200-P
Qs=1/2p-25

there is an imposition of commodity tax of 30 per unit on output.calculate pre and post tax equilibrium output and price


can anyone pls confirm me the post tax prices and quantity ?

[Eco16]

Post tax prices Ps=130
Pd=160 Q=40

[ahlashi]

im getting ps=140 and pd=170

can you pls  provide a solution

[Eco16]

Pd=ps+30
qd=170-ps
equating new dd curve and ss we get the ans.