Tangent Line Problem

I'm having a little difficult approaching this problem. Given the graph of y=x^2 an y= -x^2+2x-5 , find equations of two lines that are both simultaneously tangent to both graphs. I can easily find equations that are tangent for one graph, but finding them that are tangent to both graphs is stumping me.

Any help would be appreciated.

Thanks
Jerry

If I find the time, I'll make a nice little page with all the calculations and graphs...
Yuo will find it here:
http://www.vlaamsemolshoop.be/math/m23/