Calculating the Intersection of 2 lines

[MattRNR]

G'day again forum goers, once again i find myself perplexed by something that should be relatively simple, namely;

I need to find a way of inputting the independent and dependent values that constitute a pair of lines (see attached excel document) and calculate the coordinates at the intersection of these lines automatically (in cells; D8 and D9). Since at the point of intersection, the two line equations will have the same values of x and y, the two equations equal to each other. This gives an equation with one unknown (x) which can be solved manually by rearranging to isolate the x terms however I need some kind of conditional equation that can perform the intersection calculation for a line with any slope and direction automatically (as it will need to be repeated hundreds of times).

For the example attached the value should equate to -4 and -2

Anyone have any ideas?

Regards
MattRNR