Answer:
6c^2-cd-d^2
Explanation:
How you get the answer is you use the process called FOIL. The F is front, so you multiply the 2c and the 3c to get 6c^2. The O is the outer, so you multiply the 2c and the d(because they are on the outer sides of the parenthesis) to get 2cd. The I is the inner, so you multiply the -d and the 3c(because they are on the inner sides of the parenthesis) to get -3cd. The L is the last, so you multiply d and -d to get -d^2. The 2cd and the -3cd are the same so you have to minus them to get -cd. So the answer is:
6c^2-cd-d^2.