Given $\displaystyle u_x(x,y)-u_y(x+1,y)=xy$

$\displaystyle \displaystyle L(u)+L(v)=u_x(x,y)-u_y(x+1,y)+v_x(x,y)-v_y(x+1,y)=(u_x+v_x)(x,y)-(u_y+v_y)(x+1,y)=L(u+v)$

Is that how it should be written, the portion in red?

Or like this:

$\displaystyle \displaystyle L(u)+L(v)=u_x(x,y)-u_y(x+1,y)+v_x(x,y)-v_y(x+1,y)=u_x(x,y)+v_x(x,y)-(u_y(x+1,y)+v_y(x+1,y))=L(u+v)$

Thanks.

The color option isn't working. Which line is how it should be shown, thanks.