1. Literal Equations and Formulas
(2-5)

2. Vocabulary
Literal Equation- An equation that involves two or more variables
Formula- an equation that states a relationship among quantities

3. Rewriting a Literal Equation
One pizza costs $10 One sandwich costs $5
You have $80
How many sandwiches can you buy if you get 3 pizzas?
6 pizzas?
1st: Define your variables:
p = # of pizzas
s = # of sandwiches

4. 2nd : Write the equation
10p + 5s = 80
3rd: Ask yourself, What do I want to know?
The # of sandwiches I can buy
4th: Isolate the variable that represents what you want to know
10p + 5s = 80 (Use inverse operations to get the s by itself)

5. 10p + 5s = 80 5th: Subtract 10p from both sides of the equation
-10p p
5s = 80 – 10p th: Now divide both sides by 5
s = 16 – 2p
7th: How can we determine the number of sandwiches if we buy 3 pizzas?
-by substituting 3 in for p

6. s = 16 – 2p
s = 16 – 2(3)
s = 16 – 6
s = 10 sandwiches
How many sandwiches can you buy with 6 pizzas?
4 sandwiches

7. Literal Equations with only Variables
Solve V = bwh for height
V = bwh
bw bw
V = h bw

8. Solve ax – bx = c for x Any ideas???
Use the Distributive Property!!
x ( a – b) = c
Now isolate x
x ( a – b ) = c
( a – b ) (a – b)
So x = 𝑐 (𝑎 −𝑏 )

9. You try: Go to textbook pg 110
Write each formula and solve for the
following:
Perimeter: solve for w
Circumference: solve for r
Area (rect): solve for l
Area (triangle): solve for b
Area (circle): solve for r
Distance: solve for t
Temperature: solve for F
Area (trapezoid): solve for base 2