Question: how do you expand 3(1+11x)?
Answer: The second expression means 3 x (1+11x) so you multiply each item in the brackets and add them together....so it becomes (3 x 1) + (3 x 11x) which becomes 3 + 33x....if it was 3(1 - 11x) then it would be 3 - 33x iyswim.