what is [3/4 x 2/3 - (1/2-1/3)]12=?
[3/4 x 2/3 - (1/2-1/3)] *12 perform the multiplication in the brackets, first
[ 1/2 - (1/2 - 1/3)] *12 perform the subtraction inside the parentheses inside the brackets
[ 1/2 - (1/6)] * 12 subtract inside the brackets, again
[1/3] *12 multiply
4