Can someone check these answers: so for firm 1 i got -2(x2-x1) and setting it to 0 is x1 = -x2

and firm 2 i got 2(x2-x1) and setting to 0 i got x1=x2

Is this correct?

And I also want to draw a diagram of this so how would i go about doing that?

And also is the nash equilibrium just where x1 = x2 ie where they are located at the same place?