Please help me verify it's correct(did i do the equation correct)?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

How many verticies does a triangular prims have