PLZ HELP ME ASAP.. Which is the correct algebraic expression after combining like terms?

6 cd+ 3 c- 7 d- 3 cd+ 4d+ 1/3 c
- 3cd+ 2 2/3c - 11d
- 3cd+3 1/3c- 3d
- 9cd+ 2 2/3c- 3d
- 9cd+ 3 1/3c- 3d

What is the vertex form of f(x) = x2 + 6x + 3

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made. determine an equation to model his situation?