Sorry for my lack of knowledge but I need help with, it seems, a basic math algebra. I want to know how they got this:
$(1 - t)P1 + tP2$
from this:
$P1 + t(P2 - P1)$
I did the math and they are the same, but I want to know how to transform from top of the head. Tnx
$$(1 - t)P1 + tP2$$
$$\Leftrightarrow P1-tP1 + tP2~~~Expand ~bracket$$
$$\Leftrightarrow P1+tP2-tP1 ~~~~Rearrange$$
$$ \Leftrightarrow P1 +t(P2-P1) ~~~~ Factorise ~t~$$