Answer:
Cost of each hat: $5
Cost of each mask: $3
Step-by-step explanation:
Let be "x" the cost in dollars of a party hat and "y" the cost in dollars of a mask.
Set up a System of equations using the information given in the exercise:

You can use the Elimination Method to solve this System of equations:
1. You can multiply the first equation by -1.
2. Then you must add the equations.
3. Solve for "y".
Then:

4. Now you can substitute the value of "y" into any original equation.
5. Finally, solve for "x" in order to find its value.
Then:

The square root of -36 is 6i
Answer:
-14.29422
Step-by-step explanation:
rounded to the nearest tenth = <em>-14.3</em>
Answer:
this doesn't make sense, but it depends how big the wall is I guess