Originally posted here by xxxx123
"3 x 4 = (2 x 4) + 4"
"3 x 9 = (2 x 9) + 9"
how did you come to that conclusion?
This is just basic algebra. (a x c) + (b x c) = (a+b) x c. In this case a=2 and b=1.

How about 6x4=(2x4)+(4x4)? 2 and 4 are easily done using shifts.
Or really freaky 7x4=(2x4)+(4x4)+4

so i guess that for division we just use repeated subtration right or shift to the right,correct?
Yep. In the repeated substraction count the number of times you're able to substract.
Or shift to the right, which is a division by 2.