What is 3 (4u-2) - 2 (u+2) ?

Assuming you want to simplify this expression, you would make use of the distributive property.

... = 3 (4u) + 3 (-2) - 2 (u) - 2 (2)

... = 12u - 6 - 2u - 4

... = u (12 - 2) + (-6-4)

... = 10u - 10

You first use distributive property to solve which is 12u-6-2u-4 then combine like terms which is 10u-10 which is your answer.