\(\displaystyle x^2-2x-kx+4=0\)

How would you convert the above into \(\displaystyle ax^2+bx+c\) format?

I've tried it like this

For bx: I've tried converting -2x-kx into \(\displaystyle -x(2+k)\) by taking -x common, but that's not giving me the right roots.

What am I doing wrong? What's the rule here to form bx?

Thanks!