Answer:
Step-by-step explanation:
Answer:
First, you write an explicit formula then plug in the value of n in the formula with the term number you are trying to find, in this case the 13th term.
The steps are in the pictures
the final answer is 121 btw
The equation for Louis's purchase is: 
The equation for Kate's purchase is: 
The equation for Biff's purchase is: 
Step-by-step explanation:
First of all we have to define variables for each item involved in the purchase
Let x represent burger
y represent soda
z be the slice of pizza
Then
"Louis bought a burger and soda for $8"

"Kate purchased a slice of pizza and soda for $9"

"Biff purchased a burger, a slice of pizza and a soda for $13.50"

The equation for Louis's purchase is: 
The equation for Kate's purchase is: 
The equation for Biff's purchase is: 
Keywords: Linear Equations, Variables
Learn more about Linear equations at:
#LearnwithBrainly
Answer:
a=15
Step-by-step explanation:
Solve for a by simplifying both sides of the equation, then isolating the variable.