I dont understand how to do matricies at all, please help.

7 1 1 0 1 4

0 2 6 times 5 -2 1

3 -2 1 -3 1 -8

2 8 1 times 0 1 -1

0 5 -2 8 2 4

Solve for x and y

-2 1 2 1 3 6 -6

3 2 4 times x 2 = 19 9

0 -2 4 3 -1 8 y

How to add them??

How do you find the determinant??

How do you find the inverse??

How do you simplify??

-5 -13 x= 3 1

2 5 -4 0

A hotel has 260 rooms- some singles and some doubles. The singles cost 35$ and the doubles cost 60$. Because of a math teacher's convention, all of the hotel rooms are occupied. The sales for this night are 14,000$. How many of each type of room does the hotel have???