Economic question

The demand and supply functions of a good are given by:

P= - 1/4Qd+6.75

P = 1/2Qs + 2

I have to find the quilibrium quantity of the government imposese a fixed tax of £ 2 on each good. I know that the tax affects the supply side which is Qs.

firstly i have to get the Qs andQd one the left side on its own.

So i got for the first step:

1/4 Qd = - p + 48

1/2 Qs = p - 2

But i don't know how to move the 1/2 and 1/4 to the other side.

Multiplication?

4(1/4 Qd) = 4(- p + 48)

2(1/2 Qs) = 2(p - 2)

Let's see what you get.