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:

Answer:
1st option
Step-by-step explanation:
Given y varies inversely as x then the equation relating them is
y =
← k is the constant of variation
To find k use (3, 8 ) , that is x = 3 when y = 8 , then
8 =
( multiply both sides by 3 )
24 = k
y =
← equation of variation
Answer:
7 - 2i
Step-by-step explanation:
Here we have two complex numbers and wish to combine them. Complex numbers have real and imaginary parts. We sum up the real parts and the imaginary parts separately:
-9 - 7i
+16 + 5i
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7 - 2i This is the sum of -9 -7i and 16 + 5i.