Dear mathematicians, can you explain about mixed products of vectors?

Question

higher mathematics

As for mixed products in coordinate form, I have no questions, but the "letter" form a * b * c confuses
1) How to combine, in what order?
2) How to combine these works? For example, the expression b * (c+a) * (b + 2c ) = -2a*b*c, how to output it?
3) (a+b) * (a-2b+c)*(ca) = 4a*b*c How to output here?

Answer 1

look here, for example: mathhelpplanet.com/static.php?p=smeshannoe-proizve... .
the first example is similar to your points 2 and 3: you make a replacement, count the volume of the box.