How do I work out the gradient of a straight line without using an actual graph?

I can't find my notes on this...please help! What's the method for calculating the gradient from just a pair of co-ordinates? Without, as I say, the need for a graph?


Thanks :DHow do I work out the gradient of a straight line without using an actual graph?
take the change in x over the change in y.





For example if you had (x1,y1) and (x2,y2) the gradient would be (x2-x1) / (y2-y1)