Can someone explain dilation (in math) to me and give an example ? i've forgotten how to do it and now i don't understand it

Dilation always have to do with the scale factor. By using the scale factor, it always multiplies by the scale factor. For example (2x,5y)--> (2*2x,5*2y). The scale factor is 2. The equation enlarges the point. Another example (2x,4y)--> (2*1/2x,4*1/2y). The scale factor is 1/2. This shows reduction. In short, Anything below 1, Like a fraction, shows reduction and anything above 1 shows enlargement. Hopefully this helps.